Interesting.
What’s it like to be on the other side of “peak faith?”

Thank you for this wonderful, WONDERFUL, WONDERFUL news.
The world needs fewer self-righteous, sanctimonious people who want to run other people’s lives for them.

I am not sure who is included in the definition of “Christians” in this graph, but if you were charting membership in the Church of Jesus Christ of Latter-day Saints, that graph would be rising. As sociologist Rodney Stark has pointed out, Mormon membership has, since its initial growth spurt following its organization in 1830, settled down to a consistent doubling about every 20 years. Stark used the Mormons’ growth as an example of how a small but steady expansion can explain the growth of early Christianity in the Roman Empire, without any need to resort to the concept of mass conversions. While the growth of Mormon membership in the US is not as fast as that outside the US, it is still positive, with people not only adding to membership through conversion but Mormons having on average twice as many children as the average US family, the only religious group that beats the Muslim birth rate.
For the sake of argument, let’s have 5 million Mormons (just in the US) double every 20 years until 2240. That gives us 2 to the 11th power or 1,968 times 5 million in 2230, or 9,840,000,000 Mormons. Obviously, if we are just extrapolating current trends, all US residents will theoretically become Mormon well before that date.
If we make the doubling period 30 years instead, then before 2240 we will have over 2 to the 6th power = 64 times 5 million, or 320,000,000 Mormons. Again, the US becomes all Mormon by 2240. And there will be at least as many Mormons in other countries.
Clearly, it doesn’t seem likely that 100% would ever convert. The highest rate of Mormon citizenship in any nation currently is about 45% in Tonga, followed by 30% in Samoa.
Among the side effects will be that alcohol and tobacco use will drop drastically. Out of wedlock births will drop. The number of positions for paid clergy will be cut drastically, since Mormons use unpaid volunteers for pastors. The crime rate will also drop. Education rates will climb. Professional sports may stop playing games on Sunday due to lack of fan support, as well as refusal of players to participate on the Sabbath. A large part of the population will have lived in other nations for two years and learned to speak their languages, while millions of people in other nations will have learned English and helped create an international infrastructure for business, communications, education, and cultural sharing that will create a true international community based on deep personal ties across international boundaries. Large amounts of personal income as well as personal time will be donated to charitable organizations.
A lot worse things could happen to America.
Is this ridiculous to you? Then so is the notion that Christians will disappear from the US by 2240.

Just to be clear, I don’t think anyone should take the graph seriously. Extrapolating from a few decades of decline over a couple of centuries makes little sense. A speaking of extrapolation, you should be careful about Stark’s. The problem with Mormon statistics is that the LDS Church doesn’t take people off the rolls. According to the 2008 Trinity ARIS survey of self-identification, the number of Mormons in the U.S. increased by less than 30 percent between 1990 and 2008, from 2.5 million to 3.2.

I hope that this graph is not a true indicator of where our country will be in 2040! I admire the greatness of heart of the American Christian. I also consider myself Christian, as a member of the Church of Jesus Christ of Latter-day Saints, but recognize the doctrinal differences among us. Nevertheless, may the day never come when Christians are absorbed into the secular population! My son had an interesting experience in his high school English class. The class decided to debate the issues of whether pre-marital sex was okay, and whether gay marriage should be allowed. [I don't think English class is really the appropriate place for this]. He chose to defend the traditional Christian position on both issues and had very few supporters. He told me, “I said to the kids, ‘You’re Christians, why aren’t you helping me?’” Their answer was, “People can decide for themselves.”
If young people don’t understand that the family is the basic building block for a society, and that some behaviors threaten to destroy the family, belief will be swept away into nothingness. Please, please, teach your children about the needs of a stable society.
I would be happy to see everyone join my church, as Mr. Swenson proposed. It is true that our Church does not purge people from the rolls when they don’t attend; however, a person may remove themselves if they care to, but it requires action on their part, and many simply will not do it. Still, the LDS birthrate is higher than the rest of the nation, and the older I get, the more aware I am that having children and raising them in a productive fashion is one of the most important factors in having a great country. May more great American Christians follow our example!

You sew what you reap, lady.
Loving gay couples getting married are no “threat” to “the fambly” (TM, all rights reserved) – and certainly not to yours. They/we help contribute to this “stable society” you idolize. In fact, for the many of us that don’t have children, our taxes subsidize your children’s education.
And high school english classes are an ideal place to learn to debate. Just because your son chose to debate the losing argument doesn’t invalidate the practice.
Back to parenting class for you.