Former New Jersey Gov. Chris Christie sharply criticized President Donald Trump’s handling of religious issues, saying the president lacks understanding of faith and describing recent remarks about Pope Leo as inappropriate.

Appearing Sunday on ABC’s “This Week,” Christie also took aim at Vice President JD Vance, suggesting his alignment with Trump on religious matters could carry political consequences.

Christie said, “This vice president, who is, you know, now a Catholic convert, early on in your Catholicism, taking on the pope probably isn’t the greatest thing in the world. But, you know, JD Vance is following, as he always does the lead of Donald Trump. He cannot get out from Donald Trump’s back. He cannot ever do anything that isn’t completely 110 percent supportive of what Trump says. But here’s the problem, he’s leading himself to a real, real political problem for himself. Donald Trump knows about as much about the Catholic Church as my phone does.”

He continued his criticism of the president’s familiarity with religion more broadly.

He continued, “This is a guy who knows nothing about religion, has no religious basis at all. Ramesh and I were speaking in the green room about the time when they asked him about which one he preferred, the New Testament or the Old Testament. He goes, well, I like them both. I like them both. You know, this is a guy who’s a fake. He’s a phony. And JD I have a little advice for you this morning, don’t be following a phony on issues of religion and taking on Pope Leo. The other complication here, Jon, is, this is the first American pope. So, American Catholics not only follow him as Catholics, but they have a great pride of ownership in this pope. And so it’s personal on top of being theological.”

Christie said the situation could have lasting political ramifications, particularly among Catholic voters.

He added, “And so, I think this is a real problem politically for them. Catholics are not going to forget that this president, and my party’s leadership, has taken on Pope Leo in a really, really gross way.”