Romans 4 v 20-21



Romans 4:20-21
(20)  He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;
(21)  And being fully persuaded that, what he had promised, he was able also to perform.


In spite of the humanly impossible situation, Abraham did not waver through (lit., “by”) unbelief. “Waver” (diekrithē) means “to be divided” (sometimes trans. “doubt,” as in James 1:6). The patriarch was strengthened in his faith (lit., “was empowered [enedynamōthē, from endynamoō] by means of faith”). God, responding to Abraham’s faith, empowered him and Sarah physically to generate the child of promise. Also he gave glory to God, that is, he praised God by exalting or exclaiming His attributes. Abraham was fully persuaded that God had power (dynatos, “spiritual ability”) to do what He had promised. What confidence in God this spiritual forefather possessed! He “in hope believed” (Rom. 4:18); he was not weak in faith despite insuperable odds (v. 19); he was not divided in his thinking by unbelief (v. 20a); he was empowered by faith (v. 20b); and he was fully persuaded God has the ability to do what He had said (v. 21).
  

Walvoord, John F. ; Zuck, Roy B. ; Dallas Theological Seminary: The Bible Knowledge Commentary : An Exposition of the Scriptures. Wheaton, IL : Victor Books, 1983-c1985