There's an old joke among Catholics. "Are you a Christian?" "God no, I'm Catholic."
J D Vance is a late convert, I suppose, and I've no reason to assume his conversion isn't sincere. But, he's definitely choosing his words very carefully to appeal to evangelicals. Because he doesn't sound very Catholic. Personal journeys not pilgrimages. Faith not The Faith.
Maybe he's just finding common ground but I suspect he's just as calculated and shape-shifting in this as in everything else.