Kreeft outlines the main theological and practical differences, as well as the important common elements, between Christianity and the other great world religions.
Dialogue is almost nonexistent.
Islam resists ecumenical dialogue more than any other religion. To proselytize in any way in a Moslem country is to go to prison. Islam once nearly conquered the world, in the early Middle Ages when its empire stretched from Spain to Indonesia, and it looks as if it could do so again. Islamic growth rates in Africa and even America are phenomenal. In other words, Islam has the world's lowest rate of being converted and one of the world's highest rates of converting.