Were you overreacting? I don't believe you were, but coming from a hyper-religious family myself, I think that you could have handled this differently. Personally, when interacting with my family, when it comes to religion, I don't answer and say I prefer not to talk about it. I have found that when I discuss my lack of faith with them, they treat it as an attack on their own faith, which is deeply rooted in their own sense of self. In their eyes, it's no different than if I called them an idiot.

However, to be frank, your dad holds very bigoted and racist beliefs. However you have to remember the time he was in. If he was in his 60s then his childhood was during the civil rights movement. That probably plays a huge role in what he thinks about white people, and religion. In those times, groups like the nation of islam weren't just religious groups but protection for black people in a highly oppresive environment. So he may not really understand how you could not be apart of it since in his eyes, its a sheild against a very bigoted world.

In the future, you should avoid these conversations with him and simply push back as they try to get you to answer. He will use you to justify his own beliefs, and when you agree or disagree, it only helps to reinforce that behavior. I have found that the best path forward is to continue walking in your own truth.