‘Yet, looking to 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.'
He looked to God's promise, not wavering through unbelief, and grew strong in faith, giving glory to God and confident that what He had promised He was able to perform. And all this because of his personal faith and trust in God. Thus all the way through his life faith is what is seen to be the basis of Abraham's life.