may God guide u.
i still remember the discussions i had with our religious education teacher (an atheist who taught us his interpretation of the Bible!)
they were not always comfortable chats
when u can, stand up for your beliefs with all love and tolerance of the other view.
if u just have to listen to someone talk nonsense, go with the flow and write on your essays 'according to x's theory...' and make sure u study well the rubbish theory and get good marks (this shows u are a good student and not trying to misbehave).
but when it comes to taking part (don't do any rituals from other religions), or if u are asked a question, then say what u believe and why.
enter the situation with prayer, coming close to God in humility to receive His mercy.
remember 1 peter 3:15:
'but sanctify the Lord God in your hearts, and always be ready to give a defense to everybody who asks you a reason for the hope that is in you, with meekness and fear'.
may God give u strength.