“and being fully convinced that what He had promised He was also able to perform” (Romans 4:21).
Paul the Apostle highlighted Abraham’s unwavering faith in God by stating that, “…He was fully convinced that God was able to do what he promised” (CEB). Paul also turned to Abraham’s example to illustrate the nature of genuine faith in his Biblical letter to the churches of Galatia…
“The Scriptures say that God accepted Abraham because Abraham had faith. And so, you should understand that everyone who has faith is a child of Abraham. Long ago the Scriptures said God would accept the Gentiles because of their faith. This is why God told Abraham the good news that all nations would be blessed because of him. This means everyone who has faith will share in the blessings given to Abraham because of his faith” (Galatians 3:6-9 CEV).
One commentary provides us with a helpful perspective on these passages…
“Abraham did not know how God would fulfill His word, but that was incidental. He knew God and had every confidence that God was fully able to do what He had promised. In one way it was wonderful faith, but in another way it was the most reasonable thing to do, because God’s word is the surest thing in the universe, and for Abraham there was no risk in believing it!” (1)
This leads us to a timeless piece of wisdom that reminds us of the value of a promise: a promise is only as good as the person who makes it. The truth of that adage is undeniable, for we will inevitably encounter others who fail to deliver on their promises. However, we can rely on God’s promises, even when our external circumstances seem to suggest otherwise. To understand why, let’s consider the following attributes of God…
- God is immortal (1 Timothy 6:16).
- God is all-powerful (Genesis 1:1, Matthew 19:26).
- God is omnipresent (Psalm 139:7–12).
- God is omniscient (Psalm 139:1–4, Hebrews 4:13).
- God is immutable (or unchanging) (Malachi 3:6, James 1:17).
- God is just (Psalm 89:14)
- God is a God of truth (Deuteronomy 32:4, John 14:6).
- God is righteous (Psalm 11:7, Psalm 145:17).
While there may be some who lack the desire or ability to fulfill their promises, God is fully capable of fulfilling any promise He chooses to make. The following source addresses that reality with a comment worth considering: “Certain nouns and verbs are used in the New Testament according to Hebrew idiom. ‘Able,’ when applied to God or Christ, denotes both willingness and ability.” (2)
(1) William Macdonald, Believer’s Bible Commentary Edited by Arthur Farstad. Thomas Nelson Publishers [Romans 4:21]
(2) Smith, J. H. (2016). Romans 4:21. In The Ultimate Cross-Reference Treasury. Retrieved March 3, 2026.