"Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven ..." (Matt 7:21)(In the past I've referred to this as one of the scariest portions of Scripture. It still is. I highly recommend you read Jesus's entire thought on the topic -- Matt 7:13-27.)
According to WND, a recent Barna poll illustrates my point. This poll says that half of those who call themselves Christians don't believe in Satan. One third of them believe that Jesus sinned. Other "certainties" that they've dismissed are the command to share their faith and any notion that the principles that the Bible teaches are accurate. An earlier poll said that 75% of those who classified themselves as "born again Christians" also denied any absolute truth. Other polls say that it is an extremely popular view among "Christians" that all roads lead to God. In other words, there is a staggering number of "Christians" who are not.
But, you see, I'm not allowed to say that. It's "incorrect" to question another person's salvation. "Who are you to say?" We can't ask the question ... the one we've asked for centuries. "Are you saved?" "Are you a Christian?" "Have you been born again?" We've tried to ask it in multiple ways to differentiate between the "professing Christian" and the real Christian. In the early days it was a simpler question. It was in the form of a fish drawn in the dirt, and it was a fearful question because if you answered "Yes" to the wrong person, it could cost you your life. Today, of course, it's more "fashionable"... as long as you're not that kind of Christian ... you know ... the one with actual, biblical beliefs.
As much as people would like us to think otherwise, Christianity has a definition. There are differences between Christianity, "professing Christianity", and other religions. And, the author of Christianity -- Christ Himself -- said that there would be those who profess and even think themselves Christians who are not. You may raise your hand and object. You may insist that their view of "Christian" is just as viable as mine. But eliminate miracles (a common thing among "professing Christians") including the Resurrection and you eliminate Christianity. Eliminate Christ's sinlessness and you eliminate Christianity. Assign Christianity to a mere level of "social gospel" or "moral teaching" and you eliminate Christianity. Take the Bible out of the equation and you have ... well, nothing to stand on.
I don't actually like it much better than you do. Nonetheless, it remains a fact. Not everyone who calls themselves "Christian" are. There are big names who represent Christianity to many who are not, themselves, Christians. There are people in every arena of life, from janitor to pastor, from student to seminary professor, who claim and even believe they are Christians who are, in fact, not. Now, if there is indeed genuine Christianity and it is wrongly proclaimed by these false believers, is it not our obligation to hold out for the truth, to defend the faith? I don't like pointing out false believers as false believers, but I like less the assault on Truth that false believers entail. So I'll continue to stand on genuine Christianity against the false.