Being fully convinced (i.e. Abraham) that what he (i.e. God) had promised he was also able to perform. And therefore it was accounted to him for righteousness.
Verse 20 states concerning Abraham that “he did not waver . . . but was strengthened in faith”. In today’s verse an even stronger expression describes his faith: he was “convinced” that God would stand by His promise.
From this we learn that strong faith is not necessarily made noticeable by great deeds. It is rather childlike trust in our mighty God, who is always in a position to carry out what He has promised.
In addition, it becomes clear that genuine biblical faith means more than considering something possible or probable, as the word mostly signidfies in everyday language. There is nothing uncertain in true faith; it is based on God's own word and is therefore convincing.
In verse 3 Paul had already referred to Genesis 15 where it states that Abraham’s faith was “accounted to him for righteousness”. The whole chapter sets Abraham and David, too, as an example of anyone’s justification occurring through faith and not works. Already in Old Testament times this was no different.
We have seen that Abraham was justified not by works (vv. 2.3), nor by any religious rite like circumcision (vv. 9 - 12), nor by the law (vv. 13 - 1 5) but by faith (vv. 3 & 16 - 20).
In this he is the archetype of a believer; and in the next verses Paul draws a parallel with our own day.
(to be continued on 28th April)