How are Buddhism and Islam different?

There is a big fundamental difference: Islam involves a supernatural God, whereas there is no God or God-concept in Buddhism. Although the word "religion" can be used in different ways, it is probably best not even to think of Buddhism as a religion. For example, there is no creed of beliefs in Buddhism. Instead, it is really a set of practices that the Buddha recommended that his followers test for themselves. The Buddha recommended that his followers be skeptical of everything they didn't prove for themselves. Theistic religions like Islam and Christianity never have that kind of attitude. They do not want skeptics and doubters; they want followers. They want people willing to attach to certain beliefs.