Excuse me, but the Catholic and Baptist traditions are BOTH Trinitarian, i.e., the both view the Father, Son and Holy Spirit as a part of the Godhead.This would also include Episcopal/Anglican, Lutheran, Methodist, Presbyterian, most pentecostal/charismatic, including the majority of non-denominational churches.
The important thing is to learn of each other's beliefs, finding the points you both have in common. It can be more difficult, but it's not impossible.
Bruce
B and C got a reaction from yachachiq12 in Religious Differences between Fiancees