One common fallback argument Christians make is that theirs is the majority religion, and so that’s how you know theirs is the best one. Once again, there are quite a staggering number of errors in this claim.
First of all, it’s not a majority; the majority of the world–63%–rejects Christianity. Christianity is a plurality, not a majority.
Second of all it’s an argument from consensus, saying that something is true because so many people believe it. But reality isn’t subject to the laws of democratic governance. Indeed, if this were a valid argument, Jews would have employed it 2,000 years ago to argue against Christianity, and the result would be no catholic church. The argument today really is “Well, when we were the minority religion, arguing from consensus was a bad argument, but now that we’re in the majority, it’s a good one”.
But even worse, this argument employs equivocation and an ontological argument to say something that isn’t true at all. Christianity isn’t the largest religion.
Indeed, there’s no such thing as a Christian.
Christianity is a category, not a religion. Any faith which has as a central tenant of that faith the divinity of Jesus Christ is a “Christian Religion”. But there are (conservatively) 5,000 sects of Christianity in the United States alone, and nearly all of them are excommunicative. If you’re an Evangelical, you think every other “Christian” has the wrong faith, and is going to hell–all of them. Same if you’re a Southern Baptist, or a Mormon. If you’re a Catholic, every other Christian faith might as well be Jewish as far as you’re concerned.
There are roughly 300 million people identifying as Christian in the united states, but the largest denomination, the Roman Catholic Church, takes up only 20% of that. So when a Christian says that his religion is the largest in the world, you’ve got to realize that while he’s counting all Christians in that figure, he thinks 80% of them (at best) are going to hell. It’s a disingenuous argument at best. And when you look at the over 108 billion people who’ve lived on the planet, the vast majority have (when they’ve heard of it), disagreed with Catholicism.
And if you’re any other denomination of any religion, Christian or otherwise, 99% of all human beings ever to have lived (107 billion of them) disagreed with your notion of “god”. It takes tremendous arrogance if, in the face of all that disagreement, you feel your faith strong enough to impose it onto others.
An argument from consensus is faulty anyway, but the inflated sense of certainty that comes from the belief that yours is somehow “the majority” religion enables Christians to be far more dismissive of non-Christians than they’ve earned.