By the way, he wanted to help them. They had an issue, they couldn't figure out the time of Easter accurately.
They used the model in which the earth is at the center. Copernicus was playing around with the data and realized that he can actually forecast much better the timing of Easter.
He was a priest, loyal to the church. He said, here is a model where the sun is at the center and I can give you much better prediction of when Easter takes place.