I remember, back when I first became a Christian, hearing a Pentecostal TV preacher talking about how the Assemblies of God were the fastest-growing denomination in America.
I remember, back when I first became a member of the Presbyterian Church in America (PCA), the local campus minister telling me that the PCA was the fastest-growing denomination in America.
I remember, back when I was first having Mormon missionaries over in order to evangelize them, them telling me that Mormonism is the fastest-growing denomination in America.
As a result, I learned to be skeptical of “fastest-growing” claims, and to this day I wince whenever I hear somebody making one of them, whether they’re trying to make a particular religion sound attractive or dangerous.
My experience with this kind of claim has led me to identify what I call the “fastest-growing” fallacy, committed when an individual claims that his religion is the fastest-growing religion in some sphere and uses this to imply that its growth rate gives it some form of extra credibility.
Many people in recently formed churches and sects, especially highly evangelistic ones, like to claim that their religion is the fastest-growing or “among” the fastest-growing in some sphere (America, the world, etc.). They frequently insinuate that this gives their religion extra credibility, that it should give one special pause to consider whether the religion might be true, or that it gives one a positive reason to join their group (e.g., because it is new and dynamic rather than old and static).
In response to this, a number of things may be said:
First off, growth rates are no indication of truth, and religious affiliation should be based on truth. This is really the bottom line. It doesn’t matter how many adherents a religion has. Whether it’s true is the real test for whether one should join. Back in the ancient world, before the time of Christ, the true religion of the day—Judaism—had only a tiny percentage of the world’s population adhering to it. Monotheism was so uncommon that the pagans of the Roman world kept mistaking monotheists for atheists. But the monotheists were right, irrespective of how popular their religion was.
Second, portraying one’s religion as “dynamic” and “up and coming” is an appeal to the desire for novelty. But it is precisely the desire for novelty that must be avoided in religion. The purpose of the Christian Church is to pass down what was given us by Christ and the apostles. Consequently, anyone who advertises himself as having a novel approach is playing a risky game, one that one that frequently results in heresy. As the Church Fathers stressed over and over again, the desire for novelty was what led the great heretics into their errors.
Third, it is the nature of start-up religions to generate high-sounding growth rates. Consider the case of an individual who decides to start a new church. He begins with himself—one member. Then suppose that he convinces his wife and three children to join—five members. Then suppose that over the course of a year he gets his mom, a brother, a sister, a co-worker, and a couple of friends to join—eleven members. At the end of the year he can claim that his church has experienced 1000 percent growth. This rate dwarfs the growth rates of the recently formed churches and sects that use the “fastest-growing” fallacy—for example, the Mormons, who are notorious offenders in this area.
Fourth, and even more importantly, any claim you encounter that a particular church or sect is the “fastest-growing” is almost always going to be false. Why? Because there is some guy out there this year setting up an independent, start-up church that has a growth rate of 1000 percent or better. There are probably dozens or hundreds or even thousands of people doing that right now, yet their churches will be too small and new to be picked up by surveys. Thus the churches with the highest growth rates never even appear in surveys, because by the time they get large enough to be picked up by a survey, their growth rate will have slowed and they won’t be the fastest-growing any more.
Fifth, dramatically high growth rates are impossible to sustain in the long term. If they could be sustained, the entire global population would be converted within a matter of a few years.
Consider a start-up church with one member that gains only a single member in its first year—a growth rate of 100 percent. If it could sustain this growth rate indefinitely then at the end of the second year it would have four members, at the end of the third year it would have eight members, at the end of the fourth year it would have sixteen members, and so on. This may not sound too unreasonable. A young church might be doing well for itself to have sixteen members at the end of its fourth year. That might be quite achievable.
But the annual doubling cannot keep up over the long haul because doubling is a geometric progression that will quickly lead to astronomical numbers of converts. If a church starting with one person could double its membership every year for 32 years, then nearly the entire global population (4.3 billion people) would be converted.
The fact no one has converted the global population in 32 years heavily implies that no one is going to do so. Growth rates inevitably slow as organizations get larger. The easiest people to convert (often the family members and friends of the founders) get converted first, and as time goes along it is more and more difficult to make converts. So if a recently formed church or sect is in a high-growth period at the moment, its rate will slow soon enough.
Sixth, people committing the “fastest-growing” fallacy are often using out-of-date or misunderstood statistics. Their religion might have been the fastest-growing on some survey a number of years ago, yet its members will keep repeating this fact for years and years, even though the survey is long out of date, and their church is no longer at the top of the list on the most recent survey.
Likewise, they may have misunderstood their group’s place on the survey. For example, it may have been “among” the fastest-growing, but the qualifier “among” gets dropped when the story is told to others. Or it may have been the number two or three church in growth rate, yet since it was “near the top” its members end up saying that it was “at the top.”
Similarly, the nature of the survey may have been garbled. It may have been a survey of the fastest-growing Evangelical denominations with 50,000 members or more, but it gets reported as a survey of the fastest-growing churches in America—whether they are evangelical or not, whether they have 50,000 members or not. It may even be mistaken for a survey of fastest-growing churches in the world rather than just in America.
If one were to prefer religion based on long-term, sustained growth, the Catholic Church would be the one to prefer. With almost 2,000 years of growth, the Church today is larger than it has ever been before, with over a billion members. More than half of all Christians are Catholics and more than one in six human beings is a Catholic. And the number is rising.
For example, in 1997—the most recent year for which global statistics are currently available—the Church had an overall increase in membership of over ten million, only a little more than half of which can be accounted for by baptisms under the age of seven, and an increase in spite of the loss of members due to death and defection.
And the Catholic Church is growing not only in the world at large but in America in particular. In 1998—the most recent year for which national statistics are available—the U.S. Catholic population had an overall increase of 455,000, including 162,000 conversions to the Catholic Church (i.e., cases of people joining other than baptisms of those below the age of seven).
It may be important to point this out to those who commit the “fastest-growing” fallacy and wish to represent the Catholic Church as stagnant or declining in membership. It is especially valuable to know the number of adult conversions per year, since an anti-Catholic might attempt to dismiss American Church growth as due only to infant baptisms or immigration.
Needless to say, the Catholic growth rates in both the United States and the world dwarf what any other church is doing. Nobody else in the world gets an net increase of ten million people in a year, and nobody else in America gets a net increase of half a million people in a year. And remember that these represent net increases in membership—after deaths and defections have been factored in—so the actual number of converts is significantly higher.
Even if we look at just U.S. membership growth without infant baptism, nobody else in America gets 162,000 new non-infant members in a year, nor does any other American church have an overall increase of half a million members a year. When you really look at the numbers, the picture that those who commit the “fastest-growing” fallacy often wish to paint of a stagnant, declining Catholic Church simply won’t hold up.
Ultimately though, as we said at the beginning, membership affiliation is to be determined by truth, not popularity or growth. And in the truth category the Catholic Church wins hands down.