Romans 3:10 As it is written, There is none righteous, no, not one:
Since the fall into sin no person is righteous of themselves. However, some are made righteous through Christ:
Romans 5:18b ...by the righteousness of one the free gift came upon all men unto justification of life.
The Person whose righteousness is in view is Jesus Christ. We also read:
Romans 5:19 For as by one man's disobedience many were made sinners, so by the obedience of one shall many be made righteous.
By the OBEDIENCE of One (Jesus) many are made righteous.
The Bible speaks of two ways a man may become righteous before God: The first is if he keeps the whole law of God, and keeps it perfectly without one transgression. This is impossible to do, and the reason why God says there is none righteous.
The second way is through the perfectly obedient Jesus Christ paying for the sins for all those He died for. Thus having God impute (count) His righteousness towards them.
We should keep in mind, that obedience is something that is done. It is a work that has been performed. Remember the parable Jesus spoke of two sons that were commanded by their father to go and work in the vineyard?
Matthew 21:28 But what think ye? A certain man had two sons; and he came to the first, and said, Son, go work to day in my vineyard.
29 He answered and said, I will not: but afterward he repented, and went.
30 And he came to the second, and said likewise. And he answered and said, I go, sir: and went not.
31 Whether of them twain did the will of his father? They say unto him, The first.
We see from this parable, that obedience is doing. A mere profession (I go, sir: and went not) is worthless.
In order for Christ to make many righteous through His obedience, it was necessary that the action of the atonement be taken on their behalf. Words spoken in principle, cannot be said to be acts of obedience.
But if Christ performed the works (acts of obedience) at the cross in 33 AD, we then wonder how was it possible for O.T. men to have been made righteous?
RIGHTEOUSNESS OF O.T. SAINTS
Genesis 7:1 And the LORD said unto Noah, Come thou and all thy house into the ark; for thee have I seen righteous before me in this generation.
Genesis 15:6 And he believed in the LORD; and he counted it to him for righteousness.
2 Peter 2:7 And delivered just Lot, vexed with the filthy conversation of the wicked:
8 (For that righteous man dwelling among them, in seeing and hearing, vexed his righteous soul from day to day with their unlawful deeds;)
Noah, Abram, and Lot---all counted righteous by God.
Hmmmmnnn? How was that possible?
We're told by theologians, "Well, you see Noah obeyed God and built the ark"---yeah, but so what. None are righteous by their own works. We can be sure that Noah was not seen righteous by God because he obeyed him on some points (if you place yourself under the law then you have to keep the whole law).
Theologians also tell us, "And Abram was a great man of faith. Later, he'll offer up his only son Isaac." Yeah, but so what. That act didn't make Abram righteous. The Bible says no man is justified by works.
They also would say, "And Lot also was a just man. He did right in that wicked city of Sodom." Yeah, but again, so what. We can be sure it wasn't Lot's own works that made him righteous before God.
The only way to become righteous before God is---by the obedience of One! The obedience of Jesus Christ.
Noah, Abram, Lot, and all others that lived on the O.T. side of the cross, were made righteous by Jesus Christ's obedience.
Some might admit, "Alright. I see how that must be, so they were made righteous by Christ's obedience. What's the problem?"
There is no problem for the child of God that understands (by the grace of God) that Jesus obeyed the Father at the foundation of the world, and died for the sins of His people at that point. Thus, Christ's already accomplished obedience made Noah righteous, and Abram righteous, and Lot righteous, etc, etc.
According to the Bible there is no other way to obtain righteousness in God's sight than the finished work of Christ (at the world's foundation) which showed forth His obedience to the Father's will.