Romans 4:19

And without being weakened in faith he considered his own body now as good as dead (he being about a hundred years old), and the deadness of Sarah's womb; yet, looking unto the promise of God, he wavered not through unbelief, but waxed strong through faith, giving glory to God, and being fully assured that what he had promised, he was able also to perform.

These three verses are a restatement in depth of what Paul had already written in Romans 4:18, and are a further elaboration of Abraham's remarkable faith, wherein he believed God, contrary to every earthly consideration against it, and did surely receive the fulfillment of all that God had promised.

Giving glory to God ... is further enlightenment upon the spiritual attitude of the great patriarch. Since the thesis of Paul's discourse in this chapter dealt with the fact that God accepted Abraham's faith for righteousness, it was absolutely imperative that the nature of that faith should be made perfectly clear. It was a faith that staggered at absolutely nothing that God either promised or commanded. It has been noted repeatedly that it was an obedient faith, an obedience that went even as far as offering his son Isaac upon the altar, the very son through whom the promise of many nations had been prophesied; and that was only the culmination of a long series of tests and demonstrations of Abraham's faith, beginning with his obedient response to God's call to leave Ur, his kindred, and his father's house. Theologians who speak of the great patriarch's faith as "faith only" have apparently not taken into account the biblical record of just what that faith actually was. It has already been noted, but attention is again directed to the fact that Paul's lack of emphasis on obedience in this chapter stemmed from the imperfect nature of Abraham's obedience. Abraham, in the response to God's call, took, Terah and Lot with him; and those loved ones should have been left behind. Despite certain lapses, however, the faith of Abraham could never be called disobedient, or non-obedient. The so-called "faith" of people who refuse baptism and spurn membership in the church, and then claim that they are being saved according to the "faith of Abraham," is actually without anything that even remotely resembles the faith of Abraham.