Answer:
Actually, during the middle ages, Europe was immoral. The word "moral" is hardly appropriate to describe midieval European society. Let me see here; drunkenness, debauchery, adultery, prostitution, children being abandoned and left to die, murder, gambling, heck I think they did everything. Also everyone carried a dagger; the middle ages were so nasty, it was dangerous just to be about on the town walking around. Sorry, can't pin that one on material things, the middle ages are proof enough, that material possession has nothing to do with morality. Its the people in question.
During the middle ages, the world of Islam enjoyed unparalleled prosperity; honor killings were rare, because virtually all men followed the "four witnesses" rule, basically, none of the evils that plagued Europe, existed in the world of Islam.