Q. What do you think about Christians who remove their shoes while visiting a mosque or some such place when on holiday, or as you call it, vacation?
A. God said we can’t worship other gods (Exodus 20:3-6), but He did not say we can’t be polite to other people. I don’t think there’s anything wrong with observing the traditions or customs of other people as an expression of courtesy, as long as we don’t perceive it to be an act of worship.
As a general principle, if we’re ever in doubt as to whether an action is appropriate for us we shouldn’t take it. And we should also refrain if we think it might cause another believer to stumble. Paul warned us against putting a stumbling block in another believer’s way, or allowing something we consider good to be spoken of as evil (Romans 14:13, 16).