How could todays Mestizos believe in god, be converted to catholicism?

I can't grasp that I had native Aztec/Mayan ancestors who had their own beliefs but were coerced into believing a white mans religion. I know that the Bible says to spread catholicism. What if catholicism never was spread and the Aztecs conquered Europe and made them believe in such and such. I may be a skeptic but it is so hard to conform when having the remembrance of history.