"Behold, his soul which is lifted up is not upright in him: but the just shall live by his faith." Habakkuk 2:4
In Sunday School, I am leading my class through the Book of Habakkuk. This verse is timeless. At a time when judgment was about to come upon Israel through the Babylonian army, God reminded Habakkuk, and anyone who is willing to listen, that the one who is justified before God is the one who believes what God has said.
"Abraham believed God, and it was accounted to him for righteousness." Genesis 15:6
Through faith, Habakkuk looked forward to a coming Messiah Who would die in his place to pay for his sins.
Through faith, we have believed in a Messiah Who came and died for our sins and rose again from the dead.
By faith in Jesus Christ, I am justified before God. God accepts, not my works, but my faith in His finished work on the cross.
Habakkuk's prophecy is quoted four times in the New Testament. All four times, Paul quotes the verse, and each time he does, we get a slightly different picture of what it means to live by faith.
"But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith." Galatians 3:11
By faith in Christ, the justified sinner is delivered from the condemnation of God's righteous Law.
"For ye have need of patience, that, after ye have done the will of God, ye might receive the promise. For yet a little while, and he that shall come will come, and will not tarry. Now the just shall live by faith: but if any man draw back, my soul shall have no pleasure in him. But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul." Hebrews 10:36-39
By faith in Christ, the justified sinner procures both the promise and pleasure of God.
"For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek. For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith." Romans 1:16, 17
By faith, the justified sinner gains access to the righteousness of God Himself. I must have this if I am to enter into the kingdom of God, because I do not have any righteousness of my own.