The Word of God describes different measures of faith. We read of people who didn’t believe in Jesus, and as a result, He wasn’t able to perform works of power among them, with the exception of healing a few sickly people (Mark 6:5-6). Then there were times where Jesus rebuked his disciples and his Jewish crowds, calling them “you of little faith”.
In these instances Jesus performed miracles, acting on His own faith (Matthew 8:26). Then the Word describes a different measure of faith, one Jesus called “great faith” (Matthew 15:28; Luke 7:9). This is the same kind of faith Abraham possessed when he was fully persuaded that God had the power to do what He had promised, and that He would surely do what He said He would do.
As a result, Abraham saw the impossible become possible when his son Isaac was born. 2 Corinthians 1:20 says every promise in God’s word is guaranteed for those who are in Christ Jesus – are you fully persuaded, like Abraham was, of God’s faithfulness to do exactly what He has promised? Take Him at His Word, being fully persuaded to receive the full measure of His blessing in your life.