A question for Christians about Islam and deception?

We see something of Satan's subtle cunning in the Gospel account of the Temptation in the Wilderness. He uses Scripture and its truths simply in order to deceive and twist to his own ends. Hence we have here a faith which accepts certain parts of Christianity while not interpreting them correctly. Jesus is revered and respected -- but as a prophet. The Resurrection is denied completely -- it is claimed that Jesus didn't in fact die on the cross but that some subterfuge took place (as though the Lord would countenance such behaviour!) We are persuaded that Jews, Christians and Muslims are all people of the Book -- but how can this be? The Muslim version of the sacrifice of Abraham, which reflects the sacrifice of God's Son (only Muslims, of course, deny the sonship of Jesus) is that Abraham was prepared to sacrifice his son Ishmael. The implications are sobering indeed -- this is so central to the Christian faith that one has to wonder how the Koran can deny the identity of the son being sacrificed. If it is not a mistake (and it is hard to see how such a mistake can occur), then it has to be a lie. Jesus taught His disciples that if they followed Him they would know the truth, and the truth would set them free. Those of us who enjoy such freedom must not take it for granted.