Complex sentence: The idea that God created the world out of nothing-- "ex nihilo"--is central today to Islam, Christianity, and Judaism; the medieval Jewish philosopher Maimonides felt it was the only concept that the three religions shared.
Split into simpler sentences: The idea that God created the world out of nothing, "ex nihilo" is central today to Islam, Christianity, and Judaism. The medieval Jewish philosopher Maimonides felt it was the only concept that the three religions shared.