Let me ask you a question: Do your faiths mean very much to either of you -- or are they only something you inherited from your parents? In other words, if either of you left the religious tradition in which you were raised, would it bother you very much?
The point is this: If your faith means little to you, then you're probably right; it probably won't cause a serious problem in your marriage (at least on the surface). Perhaps one of you will give up your religion and adopt your spouse's faith; perhaps you'll both drop out. But since God means little to you anyway, it may not make much difference (unless your parents object -- which could cause friction).
But don't misunderstand me; I'm not saying faith doesn't matter in a marriage. Quite the opposite! The most important thing you can do to have a strong marriage is to put Jesus Christ at the center of your lives and your marriage. God gave marriage to us, and He alone can give us the wisdom and love we need to keep it strong, even if our path turns hard. This is why I urge you to turn to Jesus Christ today, and by faith invite Him to come into your lives. Then ask God to help you find a church where you can grow in your faith.
Don't be satisfied with a second-hand faith, but put Christ first in your relationship, and commit your way to Him every day. The Bible says, "Teach me your way, O Lord; lead me in a straight path" (Psalm 27:11).