Four times was Genesis 15:6 quoted in the New Testament. It is insinuated a number of other times. This verse is especially important in the epistles of Paul.
Just as Abraham “believed God, and it was accounted to him for righteousness” (Romans 4:3, 9, (v.23 is a partial quotation), Galatians 3:6, and James 2:23 NKJV).
Two major doctrines of the New Testament are stated in that verse: believing and righteousness. These are BIG theological words, and we want to look at them briefly.
Righteousness is a gift through trust and faithfulness (faith) in Jesus’ blood (His sacrificial and substitutionary death on our behalf). Many will agree with that statement.
Though the above is true, many will reject the notion that righteousness, from Genesis to Revelation, refers to righteous living. Righteousness includes righteous behavior according to God’s Word, dictates, and commandments. There is no such thing in Scripture as being only righteous on the inside (spiritually) without also being righteous in one's actions (physically). Internal-only-righteousness is a fantastical and imaginary doctrine taught by pulling verses out of context and reinterpreting Paul’s teaching according to a relatively modern theology!
That may be contrary to what you have believed and heard taught, but don’t be so quick to dismiss it. Read the next paragraph and look up the Scripture references. Convince yourself if it is true or not.
Internal and external righteousness are inseparable in the Bible. Bible righteousness refers to relationship, both with God and with others. There are vertical and horizontal dimensions to righteousness in Scripture. Paul and John taught both and so should we! Look at the following verses in the New English Translation (and others) to begin to get a picture of Biblical righteousness-justification. You will see doing, practicing, and living in righteousness as well as receiving the gift of righteousness. These are two sides of the same coin, and they are inseparable! See Matthew 3:15, 6:1, 11:19; Romans 3:25-26, 4:22-25, 5:17, 6:12-23; 2nd Corinthians 6:14; 1st Thessalonians 2:10; Titus 2:11-12; James 2:20-26; 1st Peter 2:24; 2nd Peter 2:21; 1st John 2:29, 3:7, 10; Revelation 22:11, Deuteronomy 9:4-6; Ezekiel 18:1-32, and there are many more.  Please read the notes.
Some are quick to reply, “But Brother Dan, it is by believing in the heart that we come into righteousness. Paul said, “With the heart man believes unto righteousness, and with the mouth confession is made unto salvation” (Romans 10:10). I agree with that verse fully, but I am telling you that our interpretation has been incomplete and we need some exposition-interpretation.
Why so much interpretation?
Recently on my Facebook feed, one pastor stated (maybe as a rebuke?), “Some want to give you Biblical interpretation instead of just accepting what the Bible says.” It was written in another language, so that is my loose version. The pastor’s statement sounds spiritual, but it’s not. It shows huge ignorance concerning Biblical language studies. If you were only dealing with modern English or Spanish, then the pastor’s statement could be applicable. When you are dealing with ancient languages and texts written thousands of years ago, that is when you are confronted with issues of interpretation.
Let me give you some examples from the English and Spanish languages. Sometimes if you look at things in more familiar terms, it may help.
Before I refer to older texts, I have been to places in the world where the English of the region was like hearing an unknown foreign language! Even in the U. S., when I first heard the people in the Appalachians speak in the mid 1960’s, I couldn’t understand ¾ of their words! I was in the car with my parents in 1964. We got lost in the mountains, so my dad stopped along a mountain road and called to a man plowing his field. When the man began to speak in answer to my dad, we were shocked. It sounded like a foreign language. Once the man finished, my dad politely thanked him, and got back into the car. My mother asked him, “Do you have any idea what he said?” Dad answered, “Wha wha wha to the right, and wha wha wha to the left.” That was all he understood after about a minute or two! We needed an interpretation!
Have you tried to read English or Spanish documents from a few centuries ago? Please try it. Suddenly, you will be faced with the fact that the language, spelling, and grammar were different than they are today. Sometimes these will be so drastically different that you will not be sure what you are reading. For the modern English or Spanish speaker, in order to get a proper “interpretation” of the text, they must go beyond reading and simply accepting the text the way it’s written. We must go further or we will misinterpret and misunderstand the text unless we find out what the words meant in their historical setting.
Unless you are an 11th or 12th century student or scholar of ancient Spanish, the oldest known poem in Castilian Spanish, El Cantar del Mio Cid, will leave question marks all over your face. Here is an excerpt:
“De los sos ojos tan fuerte mientre lorando tornava la cabeça y estava los catando vio puertas abiertas e uços sin cañados alcandaras vazias sin pielles e sin mantos e sin falcones e sin adtores mudados sospiro mio Çid ca mucho avie grandes cuidados fablo mio Çid bien e tan mesurado grado a ti señor padre que estas en alto esto me an buelto mios enemigos malos”
I am fluent in Spanish, but it doesn’t look much like it. The poem had no punctuations in the original text. That alone is a problem, but what in the world is, “uços sin cañados” or “adtores mudados”? Even if one could translate most of this poem, would their interpretation be correct? Probably not without quite a bit of study!
How about in English? Do you know the words euene, forsothe, weren, borun, watris, or erthe? They are very unfamiliar, aren’t they? All those words are in a familiar portion of Scripture from the 1395 A. D. Middle English translation in the Wycliffe Bible:
In the bigynniyng God made euene and erthe. Forsothe the erthe was idel and voide, and derknessis weren on the face of and derknessis weren on the face of depthe; the Spyrit of the Lord was was borun on the watris.
That is Genesis 1:1-2, but if you read an original copy, get ready for a real chore! The lettering style Wycliffe used is h-a-r-d to read. Do you see all the strange words I was telling you about? If you were not familiar with the text, would you have understood it? I don’t think so. I know I would be scratching my head. I would need interpretation!
A more drastic need for interpretation applies to ancient languages that existed long before Jesus walked the earth! The further back you go into the history of any language, the more you will need to study and interpret. Some words and phrases in the ancient texts make no sense to the modern reader unless you have interpretation AND historical context.
Misunderstood words and phrases
The idiomatic peculiarities of a language can be translated word for word, but unless they are explained, or interpreted, you will misunderstand the word or phrase. One short list of Hebrew idioms is found on the website: Ancient Hebrew Research Center. Here are the idioms mentioned on their list from Psalms and Proverbs. In the parenthesis to the right, I added what these idioms are not referring to. You would be surprised at the funny ways people often misinterpret these idiomatic expressions. Some I have heard are roll-in-the-floor funny!
make powerless (not a reference to losing teeth in a fight!)
set free (not a reference to getting a bigger space!)
Their throat is an open grave
they speak deceitfully
Eye is consumed
vision is blurred
Iniquity in my hands
Hearts and kidneys
thoughts and emotions (not a reference to your blood pump or kidneys!)
the portion of their cup
Little man of the eye
act purely (not a reference to hygiene after toilet use!)
Lift up my soul
pray (not a reference to coming out of depression!)
Seek my face
seek me (not a reference to seeking the face as opposed to the hands!)
Eyes are upon
Lifted heel against
turned against(not a reference to kicking someone!)
Tongue struts through the earth
arrogantly order everyone (not a reference to gossip or slander!)
defy God (not a reference to becoming great without God!)
might(not a reference to being right-handed!)
Son of wickedness
use time wisely (not a reference to length of life!)
created (not a reference to being solidly built on a foundation!)
Hide your face
refuse to answer (not a reference to being ashamed!)
Lift up eyes
look up toward (not a reference to vision!)
killed(not a reference to eating something that’s still alive!)
drains strength (not a reference to osteoporosis!)
generous (not a reference to good or clear eyesight, good luck, or wishing goodness on people!)
stingy(not a reference to being single-minded, bad luck, or putting a curse on someone!)
Fruit of the mouth
what someone says
lamp will go out
will die (not a reference to a lack of light at one’s house!)
Go to the link and read the idioms from the other books of the Hebrew Bible. There are hundreds more idiomatic expressions that are not included in that list. Any of these could be easily misunderstood unless explained.
Did you know that many words in English meant one thing years ago that today mean something completely different? Nice used to mean silly, foolish, and simple. Silly was something worthy or blessed. Something awful was something worthy of awe, and naughty used to be one that had nothing! Gay used to mean light-hearted and joyous! My, my, my, how gay has been highjacked and misrepresented! To be a husband originally meant you owned a house or land and had nothing to do with marital status. To broadcast was the way you swept your hand to sow your seeds in the field! Buxom was not related to female anatomy, but meant that someone was meek and obedient! The list could go on for many pages! 
If you only look at the English language in the last few hundred years, you will see that word order, grammar, definitions, and punctuations have changed. New words have been added, and many words have gone into disuse.
Some words from 1960’s and 70’s have disappeared! Do you remember words like: groovy, having a gas (nothing to do with passing gas!), bug, crash (nothing to do with automobile accidents!), pad (not a reference to your iPad!), and far out. Did you ever get the question, “What’s your bag, man?” Did you hear the expression, “What a bummer”? If you remember any of these, then we dated you! Most reading this need interpretation from just 40 or 50 years ago! How much study and interpretation do you think we would need for languages 2 to 3 thousand years old? It is ludicrous to believe you need to accept the text as it is written without explanation or interpretation.
If you follow the logic of the pastor that thought interpretation was not necessary, and that we should take the verses as they are written, then many Scriptures could be misinterpreted.
When the New Testament Quotes or Alludes to the Old Testament
Besides reading and studying ancient texts in their historical, cultural, and linguistic context, we must look at verses in the right context when they are alluding to other passages of Scripture.
Here is an example that will hit you like a ton of bricks because of the implication for dearly held evangelical ideas:
“For this commandment which I command you today is not too difficult for you, nor is it out of reach. It is not in heaven, that you should say, ‘Who will go up to heaven for us to get it for us and make us hear it, that we may observe it?’ Nor is it beyond the sea, that you should say, ‘Who will cross the sea for us to get it for us and make us hear it, that we may observe it?’ But the word is very near you, in your mouth and in your heart, that you may observe it (Deuteronomy 30:11-15).
First, did you notice that God’s commandments were not too difficult? That flies contrary to Christian teaching that says that the law of God was difficult, harsh, or cruel!
Paul quoted part of this portion of Scripture in Romans 10:6-10.
But the righteousness based on faith speaks as follows: “Do not say in your heart, ‘Who will ascend into heaven?’ (that is, to bring Christ down), or ‘Who will descend into the abyss?’ (that is, to bring Christ up from the dead).” But what does it say? “The word is near you, in your mouth and in your heart”—that is, the word of faith which we are preaching, that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation (NASB).
Generally, people think that our salvation in Christ is only based on believing it and saying it alone. They miss Paul’s intended and fuller meaning. The complete passage reveals something more than believing and speaking alone. Paul’s statement about believing in the heart and confessing with the mouth was also stressing that God’s moral commandments were within reach of every covenant person. God’s moral commandments were not burdensome, harsh, or cruel. (See 1st John 5:2, 3 in different translations.) They were not too difficult or out of reach, as stated in the context of Deuteronomy 30:11-15!
Come on, let’s read the context! It was as close as a word spoken in the heart or by the mouth, so that you may observe it or do it. The Word wasn’t in your heart and mouth for the purpose of agreement with Church dogma, or so that others may call you a Christian. “Believing in the heart that God raised Jesus from the dead and confessing Jesus as your Lord with your mouth” was emphasizing obedience to the Gospel of Christ, and receiving His Lordship over your life (see Romans 10:16).
The Lordship of Jesus over our Lives
Jesus taught us concerning the meaning of having His Lordship over our lives, and it is not based on spoken words alone!
“Why do you call Me, ‘Lord, Lord,’ and do not do what I say? Everyone who comes to Me and hears My words and acts on them, I will show you whom he is like: he is like a man building a house, who dug deep and laid a foundation on the rock; and when a flood occurred, the torrent burst against that house and could not shake it, because it had been well built” (Luke 6:46-48 NASB).
Speaking or confessing Jesus as your Lord, and even doubling up on it (“Lord, Lord”), is incomplete. Note the three things Jesus mentions as those that truly are under His Lordship:
You come to the Lord Jesus.
You hear His words.
You act on His Word, or you DO it!
Notice that all three parts stated together. It is a threefold cord, if you would, that cannot be broken. Confessing His Lordship over our lives was always a reference to OBEDIENCE to Him whom is Lord! It always meant obedience to His Word and will. His message to the Gentiles was that, through the gospel of Christ, they were to be brought into the obedience of faith (Rom. 1:5, 16:26).
“Not everyone who says to me, ʻLord, Lord,ʼ will enter into the kingdom of heaven - only the one who does the will of my Father in heaven” (Matthew 7:21 NET).
Just as important, we must understand that practicing the things that are in opposition to God’s Word (commandments) is a denial of His Lordship over our lives.
“On that day, many will say to me, ʻLord, Lord, didnʼt we prophesy in your name, and in your name cast out demons and do many powerful deeds?ʼ Then I will declare to them, ʻI never knew you. Go away from me, you lawbreakers!ʼ” (Matthew 7:21, 22 NET)
Others translate lawbreakers as “workers of iniquity.” Another translation says, “those that practice lawlessness.” For us in Christ, the lawbreakers are the ones who rebel against God’s Word and His will, and live based on some past work of God in their lives. Disobedience and rebellion are at the very core of lawlessness. Frankly, even if you were at one time used by, or had a relationship with God, if you have fallen away, only repentance will bring you back (2nd Peter 3:9; Luke 13:3, 5).
Those that live in the obedience of faith in Christ right now will not hear those terrible words, “I never knew you”, and “go away from me, you lawbreakers”! Thank God! Those that live in disobedience and rebellion will hear them. It will be a horribly bad day for those that were once believers, but now live in lawlessness. Don’t get angry with me over this. I didn’t say it. Jesus said it, and I am only a messenger repeating what He said.
Look at few verses down from Romans 10:9-10, and notice the connection between believing and obedience in verse 16.
But not all have obeyed the good news, for Isaiah says, “Lord, who has believed our report?” (NET)
To obey the good news is to believe the report! Did you get that? Paul made the connection, and so should we.
If you look at the Greek word επιστεσευσεν  translated as "believed" in Romans 4:3, it is defined as; to think to be true, to be persuaded of, to credit, place confidence in, to place trust in Jesus or God, and so on. It would be incomplete to think believe means only that Greek definition because the quote came from Genesis 15:6.
As we saw in previous articles in this series, Paul usually quoted from a Greek translation of the Hebrew Scripture known as the Septuagint (LXX). The Septuagint was a word-for-word translation that kept the original Hebrew word order. Therefore, to stop with a Greek definition of a word in the Septuagint or New Testament that quoted from it is to partially interpret the Scripture. Actually, it is worse than that because sometimes the Greek and Hebrew are opposed to each other. Their concepts were often worlds apart. That is why looking at the Greek alone can be VERY misleading.
Paul was not thinking pisteuo alone. If he was thinking believing alone, then why quote Genesis 15:6, a Scripture reference from a Hebrew source- the Old Testament? What was the word in Hebrew? What was running through Paul’s heart and mind as he used this Greek word pisteuo? He was quoting the Greek Septuagint translation of the Hebrew text, but he knew what the Hebrew text said and meant.
The Hebrew word translated believed in Genesis 15:6 is heemin, from the Hebrew root word aman. It does not mean Christian beliefs or to believe alone. The word is used in the sense of support, confirm, be faithful, uphold, be established, be firm, sure, lasting, confirmed, sure, verified, reliable, to trust, and to believe- in the sense of trusting that what someone has said can be relied upon as the truth. The word faithful means loyal, constant, staunch, steadfast and resolute. 
These Hebrew concepts and definitions are at the center of Paul’s teaching and interpretation of believing in Romans 4 and Galatians 3. Let’s not forget the exposition of James 2.
After looking at the emphasis in Hebrew in comparison to Greek-only definitions, these questions must be asked of every follower of Jesus after studying the definitions. I got them after reading the synonyms for the word faithful and the powerful synonym discussion on the Merriam-Webster dictionary site:
Are you a support to the cause of Jesus, the kingdom, and the Father in Heaven? Do you have the Lord’s interest in your mind and heart, or are you after your own way and will? Is it your will be done or is it His will that you want for your life?
Are you faithful to God’s Word and His moral commandments? Are these a description of your life since you declared your sworn allegiance to Jesus as your Lord? Or are you the kind of “Christian” that says “Lord, Lord” but refuses to do what He says (Matthew 7:21-23)? If you love Him, you will obey His Word/commandments (John 14:15, 21, 23, 1John 2:5)!
Are you firm, sure, and lasting in the things of God and the Lord Jesus or are you an indecisive (or wishy-washy) Christian with no moral backbone? Are you one day an upright example of Christian moral principles according to the New Testament, and the next day you act like a heathen with your words or actions?
Can the Lord depend on you? Are you reliable? Can the Lord expect you to live according to His Word and obey His dictates for your life?
Do you trust (rely fully) in Jesus and His sacrifice for you? Do you have an assured reliance on the character, ability, strength, or truth of God and His Word?
There is much more to discuss, but this should reveal that to believe in Jesus or the Gospel is not to have a mere belief, conviction, assurance, or credence. It is much more than believing alone!
I often summarize what I have learned about this pregnant word by saying it is better defined by trust, faithfulness, loyalty, and obedience to the Lord and His Word. Like righteousness, it is a covenant term used of the faithful, loyal and obedient, and it describes relationship with God and with others. There is no believing without trust. There is no believing without faithfulness and loyalty. Don’t say you believe the Gospel and yet disobey and rebel against the Lord and His Word because these are completely incompatible!
The obedient to God and His Word/commandments are the ones that truly believe. All others are pretenders and need to repent!
 For “a fresh look at the old doctrine of justification by faith”, see Dunn and Suggate, The Justice of God (W. B. Eerdmans: Gran Rapids; 1993) pgs. 31-42. I will email you a 22-page PDF on this subject by James D. G. Dunn. Request it at firstname.lastname@example.org. There is no charge for the PDF.
 From πιστευω- See Strong’s Exhaustive Concordance, G4100- pisteuo; Thayer’s Greek-English Lexicon 511a.
 If you can handle a scholarly, difficult, and sometimes boring book, see Thorleif Boman: Hebrew Thought Compared to Greek, (SCM Press LTD, 1960) for further study. The differences between these two languages and their ways of thinking are truly monumental! For the benefit of any detractors; I am not saying that Hebrew is to be preferred above Greek as a language, or that Hebrew is in general better than Greek. The Greek language brought us science, mathematics, philosophy and many other things. Greek has value in its proper place. It would be ridiculous to deny the clear influence and contribution of Greek culture to most of the world. In these studies, I am only referring to the importance of the Hebrew language insofar as Biblical interpretation goes. In the case of Biblical thought and interpretation, Hebrew is highly preferred, and should be primary. If you haven’t done it, read the previous articles in this series.