A religious American will find Europe quite secular. Atheists can hold any office anywhere in Europe; one does not need to be (or pretend to be) religious in order to get elected for anything; teaching creationism is out of the question, I'm sorry, and everyone accepts evolution. Religion is nowhere to be found in everyday life and demanding policies based on religion is frowned upon. An interesting side effect is that opponents of gay marriage need to find contorted non-religious rationalizations for their position.

Also, the majority of Europe actually speaks foreign languages - in some regions you'd be hard pressed to find an English speaker. Don't go anywhere near border areas if you don't speak the language of at least one side as people usually don't bother with a third language once they master their neighbours'. A notable exception is the Netherlands where everyone speaks English - but it's still hard to find a job if you don't speak Dutch.