And yes...it's the largest church in New Jersey. It's the Largest Church in New JerseyPhotos really don't prepare you for its size. More Than a Church, It's a Piece of New Jersey HistoryThe Cathedral Basilica of the Sacred Heart has welcomed visitors for generations. And plenty of visitors simply stop by because it's one of the most beautiful buildings they've ever seen. If you've never stepped inside New Jersey's largest church, it may be time to change that.