Denominations

Q: If Christianity is Christianity - how do we deal with those of other denominations who are convinced that theirs is the only correct belief system?

A: I went on a summer mission trip years ago when I was in college. I remember something that the director said that I thought was profound. I think it applies here. He said...
"In essentials, unity; in non-essentials, liberty; in all things, charity." Basically, what that means is:

* There are certain things that are non-negotiables in the Christian faith. Some of these are that Jesus is the only way to God; that He died a substitutionary death for us for our sin; that God exists in three persons, Father, Son, and Holy Spirit; and that the Bible is the inspired Word of God. This list is far from exhaustive. We believe that, in order to call oneself a Christian, there must be a belief in and a trust placed in these essential truths. If someone believes something else, then historic Christianity would probably say that that person is not a Christian, but something else.

* There are also certain things that are negotiables: how to baptize (dunking or sprinkling, infant or believer), how to take Communion (intinction or wafer, wine or juice), what songs we should use in worship (hymns or contemporary worship songs or secular music), what version of the Bible to use (KJV, NIV, NRSV, NLT), and so on. These are not really essential to having a saving knowledge of Jesus Christ. Because of that, we can show each other some liberty to believe differently than what we believe in those areas. It shouldn't affect how we view that person's relationship with God.

* In either of the above areas, there should always be charity shown. Charity is an old word for love. We should always be loving, no matter the circumstance. The problem seems to come when we find that we differ in our beliefs with others, whether it be in negotiables or non-negotiables. Too often we - as Christians - respond with vitriol, scorn, and pride. We look down on and argue with others who believe differently, instead of loving them despite our differences, as Jesus would do. Would Jesus refuse to hang out with someone because they believed differently? Those are exactly the people He did hang out with. As a result of us not modeling Jesus, those who don't consider themselves to be followers of Christ / Christians see this infighting and ask, "Why would I want to be a part of that? They can't even get along with each other." That's a problem.