What did Abraham do instead of staggering in unbelief?
Instead of staggering in unbelief, Abraham believed God, who was rich in mercy toward him. God had promised that from his ninety-year-old wife and from that child He would build a nation. Abraham is set forth as the epitome of faith because he trusted God's promise rather than doubting.
Les explains that Romans chapter 4 uses Abraham as the epitome of faith. When Abraham was 100 years old, God told him he would have a son through his 90-year-old wife, and from that child God would build a nation. Romans 4 says Abraham staggered not in unbelief, but instead he believed God, who was rich in mercy even to him. This illustrates justification by faith—God justifies freely by His grace through faith in Christ's shed blood, not by works or religious deeds.
He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;