And you are assuming that Christians are so brain washed we have never thought outside the box, which is blantantly false.
BTW, we have some atheists members who want people of faith regardless of what faith to "think outside the box" and deny the validity of all religions.
Universal salvation is not taught in the Bible and I doubt it is taught in the Qu'ran so you are in a minority; a minority that refuses to take a stance. Have you read the opening chapters of Revelation, especially the letter to the church of Laodicea?