You have a different belief system than your boyfriend does and if you want to have sex with him then you have every right to discuss this possibility and all the things it involves (safe sex especially).

I think you have to know yourself and your boyfriend well enough to know that you want him to be completely comfortable with the situation or else it won't be enjoyable for either of you. I think the best thing to do is to keep an open discussion about the topic of sex and wait until it seems you are both ready.

Because you already know your boyfriend's reservations, you should make sure you both agree verbally before taking any action. It is your boyfriend's responsibility to not have sex with you if that is against his beliefs. He should not act and then blame the results on you, making you the "mistake." I think this is a possibility you really have to discuss with him so that it will be clear that if anything sexual happens in your relationship, it will be because of both of your actions.