Can they? Yes, it is possible, but not without great effort.Both religions advise against this. 2 Corinthians 6:14 says: “Do not become unevenly yoked with unbelievers.” 1 Corinthians 7:39 similarly states that one should marry “only in the Lord.”I will not discuss which one of the two religions is or is not in the Lord; but each one considers itself to teach the truth. As one of Jehovah’s Witnesses, with relatives of many other faiths, including Catholics, I can state from experience that it will be difficult because of the differences in beliefs and practices. Especially is this true if and when children come along.Jehovah’s Witnesses desire to raise their children to serve Jehovah. (Deuteronomy 6:6, 7; Ephesians 6:4) We do not celebrate the majority of things that Catholics do, holidays, birthdays, etc. My understanding is that Catholics feel that they must rase any children to be Catholics. Can you see the possibilty, even the probability, for conflicts here?The majority of Jehovah’s Witnesses take our obedience to Jehovah very seriously, and from what I know, most Catholics feel the same way about their beliefs.Of course, if you are both willingly going against your beliefs, perhaps they are not of great import to either of you.However, if you are determined to do this, we do have some helpful information on our website on how to have a successful marriage. Links provided below in the “Related Links” section.