Paul told Felix he had only been in Jerusalem a short time and could not be rightfully accused of causing any kind of trouble in either the Temple or any synagogue.
He told Felix the Jews couldn’t prove any of their accusations.
Paul did confess to believing in Jesus, “the Way”, and in everything written in the Jewish Law and by the Jewish prophets.
He told Felix he was minding his own business, purifying himself in the Temple, when the Jews from Asia, who weren’t present at the trial, started a riot and tried to kill him.
Paul made it clear that the Jewish council had no legitimate charge against him, except his belief in the resurrection, which was hardly a reason for incarceration.