Abraham described in Romans 4.19-21:

He did not weaken in faith when he considered his own body, which was as good as dead (since he was about a hundred years old), or when he considered the barrenness of Sarah’s womb. No distrust made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, fully convinced that God was able to do what he had promised.

The power of God is emphasized at the start of Romans relating to the resurrection of Jesus (1.4).  The power and the glory, in contrast with weakness and shame show up in interesting places in Romans.  Here, I’ve emphasized to words both rooted in “power” (dynamos).  Though Abraham is weak, his faith is strong.  How can that be?  It seems faith is measured by the object of faith, not the strength of the believer.  God is omnipotent so no weakness in or around Abraham can make him weaken in faith.

(If “waver” sound related, that is somewhat illusionary.  I’m still trying to figure out what the translators are doing 1n 1.20)