I don't know about 'renouncing faith', but Dylan shows up at Chabad houses on most Jewish holidays. I am unaware if he's showed up for communion anywhere lately.
He told Diane Sawyer that he firmly believes in the second coming...he also continued to write Chritian themes in songs, such as the song Ring Them Bells, and he continues to perform several of this strongest Christian songs, "I Believe In You", "Saving Grace", and "Solid Rock"....
I know some Jewish Christians who do take part in Jewish holiday rituals....after all, Christianity is a continuation of one faith.
Is all of the above hands down proof?...No...I only know that the biographers were wrong when they said he renounced is faith after three years....some songs he wrote later certainly seem to dispell that claim.
Wonder what he's talking to his Jewish friends about?