Abraham is a man of such monumental faith, and yet this is a warning to us. Even a veteran in the faith, somebody who had done great things by faith and withstood immense pressures, can fall to an old sin. So we can if we are not watchful. With the help of God, we never will, but if we are not watchful we can do so easily. Somehow, after a lesson, conscience can lose its edge, and we can forget that lesson and slip back into it. What were our old sins our chief sins before we were converted? Worldliness, jealousy, ill temper, gossip? Has it come back? Have we not watched and kept it at bay? Even godly Abraham could slip back, and it was so unnecessary, because, it turns out, God had provided for him.
What curious mixtures we all are. We have much faith in some areas, and there are other areas where we don't have much at all. Abraham and Sarah have the faith to obey God and leave Ur and then Haran a little later. They have the faith to go into unknown territory, places they hadn't yet been shown, places that would be hostile; they have the faith to leave a very civilized Ur and go into the unknown. And yet they don't have the faith to walk entirely in accordance with God's promise that he would keep them and they would be safe. So they take precautions of a humankind and make arrangements exactly like us. There are things in which all of us have shown great faith as children of God. Yet there are things which we've handled very badly and shown very little faith. So we are all searching for a more consistent Christian life and to be more universally faithful in our lives and steps.