Let me clarify a bit about influences. People get so afraid of some fellow selling kefirah. Even though most people have zero interest in what s/he is saying, and there are many places to go to find the truth.
Yet, when a sensitive soul is bothered by the more indifferent attitudes around him, nobody thinks how he is being affected. For example, if you have a whole class that doesn’t wash, make berachos, or say birchas hamazon properly, at least one boy will stop keeping shabbos.
This is a problem being among non-Jews even without any hashkafah challenges. You have to know your weaknesses.