Study of the Scriptures shows that by the progressive unfoldment to us of God's commands we are called to part with all that is not Christlike, even though it be as the giving up of a right eye or a right hand or an Isaac. This is made manifest through experience and the study of Abraham's trial as recorded in the book of Genesis.
After Abraham was called to get out of the land of the Chaldess, away from his country and his father's house; after he was forced out of Canaan into Egypt by a famine; after he was obliged to fight with four kings to rescue Lot; after Sarah was taken from him by Abimelech, and in many instances he had been called to endure hardships and difficulties,—perhaps he thought within himself that the storms had all blown over. Soon, however, he encountered something which was sharper than any other trial. God appeared to him, calling him by the name which had been given him in confirmation of divine promise and which signified "father of a great multitude." In implicit faith and obedience to divine wisdom he answered, "Here am I."
Probably Abraham expected some renewed promise, but it was a test of his faith that was required. Strong faith is often developed through mental or physical trials and put into higher service, as a scholar who has improved well his opportunity is put into a higher form. Job was tried, or lifted up, that he might be not only a good man but a great man. The difficulties of Sarah's faith were very great, but "she judged him faithful who had promised," and being convinced of this she truly judged that God could and would perform it, how impossible soever it might seem to material sense. The kindness and love of God had come to her in the knowledge of His truth, and the faithfulness of God was her security. Our fidelity to God depends upon our understanding of His faithfulness in all things.