My own approach is to respect and be friendly to everyone at first acquaintance no matter who or what they are, but if there are certain things about their behaviour or their beliefs that I don't agree with, then sooner or later I will gently point out to them the error of their ways.If they see sense, i'll continue being friendly and respectful towards them, but on the other hand if they refuse to change, then my friendliness and respect towards them will cool, I'll still be polite towards them, but i'll begin steering well clear of them.You see, if we were to keep associating with them, it'd not only give them the impression that we condone their wrongful behaviour, but their bad vibes would drag us down.That's why we have to draw the line somewhere and there's plenty of scriptural support -"He who walks with the wise grows wise, but a companion of fools suffers harm" (Proverbs 13:20)"Do not be yoked together with unbelievers. For what do righteousness and wickedness have in common? Or what fellowship can light have with darkness?" (2 Cor 6:14)"Bad company corrupts good character" (1 Cor 15:33)"Withdraw from disorderly unbelievers" (2 Thess 3:6)"Don't mix with unbelievers" (2 Thess 3:14/15)"Keep away from profane babblers" (1 Tim 6:20/21)"Don't receive unbelievers into your house nor greet them" (2 John 1:10)In fact I've seen with my own eyes the horrific effect of not obeying those scriptures - a Christian couple of my acquaintance regularly socialise with assorted nonchristians, actually regarding them as friends and having them round for dinner etc, but sadly their bad vibes have destroyed the couples own faith and they're in a terrible confused disorganised state as a result..It's something like how Kryptonite weakens Superman, bad nonchristian vibes weaken Christians.(PS - I've warned the couple but their strength of will has been so sapped by their nonchristian 'friends' that they haven't the strength to dis-associate themselves from them)