Romans chapter 4

vs 17

Abraham is a father of faith, if you will. Perhaps the Jews read Genesis more literally, thinking that "father of many nations" meant in fact two. Makes me wonder how often we might read something too literally. Or whether God preps the Bible to have multiple correct meanings dependent on interpretation.

For Paul, God is described in two ways - bringer of new life, and creator. And in that order.

vs 18

Against all worldly hope, in godly hope he believed. That verse is a classic example of simple idiomatic phrasing that could be confusing if you were reading too literalistically.

vs 19-20

I think Paul is being fairly liberal here when he says that Abraham didn't waver through unbelief or weaken in faith. Are those statements ignoring Ishmael? I would say that Ishmael was a son of unbelief. Perhaps Paul would say that he represented Sarah's unbelief, not Abraham's.

The strengthening that Paul speaks of may well be regarding the multiple elucidations of the covenant that come in chapters 15 and 17 as Abraham considers how God will fulfil his promises.

vs 21

Abraham may well have been fully pursuaded after the visit of God and the angels to his tent. Not sure if he was fully persuaded before that. I mean, I think he was fully persuaded that God's promises would be kept, but not in the literal way they were to be kept.

vs 22

If Abraham is the poster boy for faith which is credited as righteousness, then he is the perfect candidate for proving that this faith comes from God. Because we all know that Abraham was not a pillar of strength. He was just a guy.

vs 23-24

So Abraham, who had to believe that God would fulfil his promises through an as yet unconceived son, is the model for the Christian faith. We believe that God raised Jesus from the dead. Abraham's was a future hope (although I guess he still had to have faith that God's promises would be fulfilled through his son). Ours is a past hope - Jesus has already died and been raised - but we also still need to have faith that God's going to continue making good on his promises.

vs 25

This verse may well be an extra statement of power regarding the resurrection. Since our faith is centred on Jesus being raised from the dead by God, we have to recognise that without both the death for our sins, and the resurrection for our justification, the job would not be complete.