'Heresy' in the Bible

For we have found this man Paul a source of mischief and a disturber of the peace among all the Jews throughout the Empire, and a ringleader in the heresy of the Nazarenes.

But this I confess to you--that in the way which they style a heresy, I worship the God of our forefathers, believing everything that is taught in the Law or is written in the Prophets,