We pass by a period of several years. The number of years we cannot tell, but Isaac, the child of faith and promise had been born, and had grown to be a young man. Abraham’s faith had grown stronger and more intelligent, for he had learned that God fulfills His own promises. But God is a faithful teacher, and does not allow His pupils to leave a lesson until it is thoroughly learned. It is not enough for them to see and acknowledge that they have made a mistake in the lesson that He has given them. Such acknowledgment of course insures forgiveness; but, having seen the error, they must go over the same ground again, and possibly many times, until they have learned it so well that they can do without stumbling. It is solely for their own good. It is no kindness on the part of a parent or teacher to allow his children to pass by lessons that are unlearned, simply because they are difficult. So “it came to pass after these things, that God did prove Abraham, and said unto him, Abraham; and he said, Here am I. And He said, Take now thy son, thine only son, whom thou lovest, even Isaac, and get thee into the land of Moriah; and offer him there for a burnt offering upon one of the mountains which I will tell thee of.” Gen. 22:1, 2.