Abram believed the LORD, and he credited it to him as righteousness.
Genesis 15:6 is one of the most important verses in all of the Bible and it is quoted several times elsewhere. In it, the formula for salvation is given.
Abraham was given righteousness. He did nothing to earn it aside from believing. Abraham did not live a righteous life. He didn’t follow a bunch of ceremonial rules. All he did was believe God.
Belief is the key to salvation. In the church era, we are saved by our belief in Jesus Christ. We don’t just believe that Jesus lived but rather that He lived a perfect life, died on the cross for our sins, and then was raised from the dead by God the Father. Because of this our sins are forgiven.
Belief is expressed in different ways. In Romans we are told to “confess with our mouth that Jesus is Lord.” In the Old Testament belief was expressed by participating in the sacrificial system. There was no magic involved in the sacrifice that caused forgiveness of sins. Instead it was belief that God would forgive. Forgiveness was ultimately granted when Jesus died on the cross.
We can’t be righteous on our own. It takes belief in what the Lord is doing and it takes God to grant that righteousness to us.