“And here at the outset I must deal with an unpleasant business. It seems to the layman that in the Church of England we often hear from our priests’ doctrine which is not Anglican Christianity. It may depart from Anglican Christianity in either of two ways: 1) It may be so ‘broad’ or ‘liberal’ or ‘modern’ that it in fact excludes any real Supernaturalism and thus ceases to be Christian at all. 2) It may, on the other hand, be Roman. It is not, of course, for me to define to you what Anglican Christianity is – I am your pupil, not your teacher. But I insist that wherever you draw the lines, bounding lines must exist, beyond which your doctrine will cease either to be Anglican or to be Christian: and I suggest also that the lines come a great deal sooner than many modern priests think. I think it is your duty to fix the lines clearly in your own minds: and if you wish to go beyond them you must change your profession.”
(C. S. Lewis, Christian Apologetics in God in the Dock: Essays on Theology and Ethics)
This advice applies far broader than just the Anglican Church. What makes you a "Christian"? In order for that word to have any meaning there must be boundary lines that define it. If a Christian is "x", then by definition that means he or she is not "not x." Truth is by definition exclusive. We must heed Paul's warnings in Ephesians to maintain unity, but the quest for unity cannot go so far as to make us universalist. Many of Christ's claims were exclusive. He is the way, the truth and the life, not a way, a truth and a life. We must be unified within certain boundaries, but a boundary-less Christianity is no Christianity at all.
There are pastors in Christian denominations today who deny the divinity of Christ, the virgin birth, the exclusiveness of Jesus' atoning death or even the existence of a real, personal God. Echoing C.S. Lewis, I ask these pastors why they maintain their affiliation with Christianity? There are organizations (such as the Unitarian Universalists) who would openly welcome their theology. Why continue to affiliate yourself with an organization whose precepts you do not accept instead of joining one with which you do?
Unfortunately, too many Christian denominations are tolerating this type of behavior. In our effort for unity we refuse to hold people accountable when they step over those boundary stones. We can have an open and honest discussion of what those boundaries should be. But the postmodern approach taken by many Christians today is simply to let everyone define their own boundaries, until we end up with a hodge podge group of people all claiming unity but with no uniformity whatsoever.
What makes someone American? They must have been born in the United States or gone through the citizenship process. What makes someone a lawyer? They must have gone through law school, passed the bar exam and been licensed by their state. What makes someone a member of a fraternity? They must have gone through the pledge process and been accepted into the group by the brotherhood. What makes someone a Christian? Do we have an answer? Every label requires a definition. Why are we so afraid to talk about the definition of Christianity?
This isn't insensitivity. It is common sense. I am not saying that you must believe the precepts of Christianity. What you choose to believe is up to you (although you must also accept the consequences of your choice). Believe what you want. I will defend your right to your honestly held beliefs. I may disagree with you and would love to have the opportunity to discuss it, but I am not going to force you into anything against your will. But I am saying that if you want to call yourself "Christian," then you are declaring that you accept at least the basic precepts that the term is supposed to evoke. If Christianity has no boundaries then it is only a synonym for "humanity." It seems that many "Christian" churches today want to be the Church of Humanity rather than the Church of Jesus Christ.
Perhaps you think this is desirable. Perhaps you believe that anyone who calls themself "Christian" should be entitled to use that label. But as I mentioned before it is unbiblical. It also makes true evangelism impossible. How do you tell someone about Christ? Which Christ? If we cannot even agree on the answer to that basic question then we cannot agree on our message. This leads to confusion and eventually the death of your group identity.
Jesus welcomed sinners, but he still required that they come to Him on God's terms, not theirs. As his emmissaries, we must do the same. Where will you set the boundaries?