Although I understand what you’re saying, I don’t entirely agree. In spite of its colonial heritage in North America, Christianity wasn't started by white people, and the religion was and is not owned by them. Also, although I won’t waste your time with proselytizing, I want to make it clear that my faith doesn’t rest in white supremacist notions of who I am or what Blackness is.
Regarding your final sentence, as far as I’m concerned, it will take much more than rejecting religion to dismantle racism. As you said, it’s a systemic issue. The way that people regard virtually everything needs to change.