In reading Romans chapter 4, Paul is writing concerning "righteous standing" before God through faith in Jesus Christ. He explains that righteousness is not a level of achievement. He uses the example of Abraham, father of the Jewish nation,(and more as we will see.) God made a promise to Abraham that although he and his wife are old, 90 and 100 years, he would be the father of many nations and have more offspring than could be counted. At one point in the account in Genesis, it states that Abraham believed God and his faith was counted as righteousness. Genesis 15
Not that Abraham earned this status of righteousness before God by obeying a set of laws or by earning it as a wage for hard work, but that he believed God. Righteousness through faith.
The righteousness that was credited to Abraham was a gift and a blessing from God, because of God's grace upon him. God blessed Abraham because God wanted to. God has also given us a promise that we can believe. He has given it to us as a gift, not a reward.
That promise is explained by Paul again in Romans 4:24-25 "23 The words “it was credited to him” were written not for him alone, 24 but also for us, to whom God will credit righteousness—for us who believe in him who raised Jesus our Lord from the dead. 25 He was delivered over to death for our sins and was raised to life for our justification.
Romans 6:23
For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.