Nicolaus Copernicus was a Catholic. He got offered a job as a Catholic Canon(as said in THE EARLY LIFE OF COPERNICUS), from his uncle, Lucas Watzenrode. He was deeply religious, and was deciding to publish his ideas or not. Actually, his first system was presented in the Vatican gardens in 1533, before the Pope Clement VII who approved, and urged Copernicus to publish it around this time.
He was also urged to publish it to Catholic Bishop Guise, Cardinal Schonberg, and the Protestant Professor George Rheticus. Copernicus is sometimes referred to God of his works.