How do you break up with someone who doesnt have the same faith as you?

That would depend on what faith you are. Some faiths (religions) are quite explicit as to accepting someone who has different beliefs. However, it should be the same as any other break-up, do it and get over it. If you are too attached to your significant other to do so, accept that you and they are different. Peace starts from within yourself - not from someone else. Figure out who you are and if you can accept them as they are, don't expect them to change.