“Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, being fully persuaded that God had power to do what he had promised.” Romans 4:20-21 (NIV)
The Bible gives us the stories of people of long ago who believed that God was a promise giver and a promise keeper. Once such example was Abraham who had faith in God's promise. Abraham received promises from God and he had no doubt about God's ability to do what He said He would do even when Abraham did not know how God would do it. We must have the same attitude. God did keep his promise to Abraham and He'll keep His promises to us also. Our verses say that Abraham was fully persuaded about God's ability to keep promises. Let's have the same faith and attitude and not waver at all in our thinking about God's faithfulness. He can be trusted, for He who promised is faithful.