By talking to my Mama about my beliefs, I want to establish a mutual understanding of one another; however, she is quick to refuse and when I try to talk to her about it rationally, she takes it personally (when my questions are meant as no offence).
My Mama too, when she was alive and I was a kid. Some people just are that way. They don’t see how much we rational ones long for understanding. They only see that we aren’t fitting the mould—their mould—and that offends them. The only answer I have is to live as best you know, be the best person you can be, and hope for the best. Perhaps the relationship is strong enough to withstand the test when she discovers your lack of belief in her god, but no guarantee. Christianity is very particular about this and the religion can and will divide families. Christians takevery seriously:
whoever loves son or daughter more than me is not worthy of me.
It forbids them to accept an atheist child. Your question is a very common one. It is so sad.