21 and being fully convinced that what He had promised He was also able to perform.
21 and being fully convinced
The idea of “fully convinced” is wholly certain. Abraham was convinced fully in what God was able to do. Abraham was fully settled in his mind about this. No doubt his faith was tested as he and Sarah grew older.
The word “fully” leaves no room for doubt. Our confident faith rests solely on the unembellished Word of God. There is a naked element to our faith. We cannot adequately believe God without believing the Bible.
He 11:1, Now faith is the assurance of things hoped for, the conviction of things not seen.
that what He had promised
God’s promise to Abraham was an unconditional promise, a free promise given by God without solicitation. The Greek indicates that God made the promise at some point in the past of Abraham’s life and continued the promise on a permanent basis (perfect tense).
“Promise” is a recurring theme in Romans 4 (vv. 13, 14, 16, 20). The verb “promised” occurs in this verse. The unconditional promise to Abraham is a promise of unadulterated grace. The only condition to receive grace is faith grounded in God’s commitment to us.
He was also able to perform.
If we believe the Bible, there is no question about the ability of God. Since He is omnipotent, all potent, He is able to fulfill His promises to us. This idea rests at the basis of our faith in Him. This is unqualified faith in God’s ability.
Our faith is in the assurance that we know a God who promises unconditional grace to us.
When we have assurance in God’s promises, we glorify His name. We then have complete conviction that God will do what He promises. True faith always has this assurance. Christians are completely sure of what God commits to them. God saves us, not because of our faith but because of His grace, His promise. True faith simply receives His promise. This is trust in God’s character and work for us.
The reason Christians can have assurance in God’s promises is because it does not reply on self or circumstance but on God Himself. Faith grounded in self is weak faith. Faith grounded in the character of God is strong faith. God is faithful to us. All of this requires significant knowledge of God’s Word.
Ge 18:14, Is anything too hard for the Lord? At the appointed time I will return to you, about this time next year, and Sarah shall have a son.”
Eph 3:20, Now to him who is able to do far more abundantly than all that we ask or think, according to the power at work within us…