Why did Nicolaus Copernicus believe in the heliocentric?

Answer 1

There is no evidence that he believed the heliocentric theory but his motivation in putting the theory forward was to provide a model of circles and epicycles that provided a simpler model for predicting the planets' positions than the old Ptolemaic theory. It worked quite well and was accepted by the church as a valuable teaching aid, while they retained their theological beliefs about the Earth being in fact at the centre.