God never intended Abraham to slaughter Isaac.  From the beginning of the story, which speaks of God testing Abraham, and from the end of the story, when Abraham is told not to. Abraham, on the other hand, out of fear of God, was willing to violate God’s moral law in faithfulness to God’s command.

God does not want even his most God-fearing adherents to go so far as to murder in his name or even at his command.   The angel orders Abraham “not to do anything to [the boy].”  We are being told, God will never ask for this kind of proof of loyalty or fear of God again. He only asked it of Abraham, the first forefather of the Jewish people, to demonstrate Abraham’s boundless fear of God.

Abraham is praised for being prepared to do what we may not do, and because God, the source of all morality, asked Abraham to do what no moral person before or since should ever contemplate.