Just wondering, how can you be half Christian and half Muslim?
Don't some of the views counteract with each others? Maybe I'm wrong, I only know about Christianity, but I'm guessing some might conflict?
Or are you just not religious at all, and you are simply referring to being half half because both your parents are different religions?
Don't become a satanist and do what not, it won't work.
I suggest you just leave it. Whenever someone makes a joke, just walk away or say straight out "I don't want to hear it". They will eventually realise how childish they are being.