God Never Ordered Abraham to sacrifice his son
God is the Most Merciful. He never violates His own law (7:28). Any person who believes that the Most Merciful ordered Abraham to kill his son cannot possibly make it to God's Heaven. Such evil thought about God is grossly blasphemous. Nowhere in the Quran do we see that God ordered Abraham to kill his son. On the contrary, God intervened to save Abraham and Ismail from Satan's plot (37:107), and He told Abraham: "You believed the dream" (37:105). Undoubtedly, it was a dream inspired by Satan. God's irrevocable law is: "God never advocates sin" (7:28)
Killing an innocent soul is a sin. Abraham's son Ismail was innocent, he committed no evil to be killed. Thus if God had truly commanded Abraham to kill Ismail, it would have meant that God commanded Abraham to commit a sin. Many Muslims will insist that God only did this so as to test Abraham and see wether Abraham loves God more or his own son! However this logic is totally ridiculous. Indeed God tests all of us, but he tests us in upholding His commandments, and not breaking them!
Suppose you have a 12 year old son and you taught him all his life that stealing is wrong and that he should never steal any money and for any purpose. Now suppose that one day you wish to test your son, would you test him by commanding him to go and steal some money for you? Would you command your own son to do what you taught him all his life that is wrong, to see how much he loves you?