Jamieson, Fausset and Brown on Acts 24:14-15

14-15. But this I confess to thee--in which Felix would see no crime.

that after the way they call heresy--literally, and better, "a sect."

so worship I the God of my fathers--the ancestral God. Two arguments are contained here: (1) Our nation is divided into what they call sects--the sect of the Pharisees, and that of the Sadducees--all the difference between them and me is, that I belong to neither of these, but to another sect, or religious section of the nation, which from its Head they call Nazarenes: for this reason, and this alone, am I hated. (2) The Roman law allows every nation to worship its own deities; I claim protection under that law, worshipping the God of my ancestors, even as they, only of a different sect of the common religion.

believing all, &c.--Here, disowning all opinions at variance with the Old Testament Scriptures, he challenges for the Gospel which he preached the authority of the God of their fathers. So much for the charge of heresy.