When I was a kid, I was always curious about why there were so many different kinds of Christian churches in America: Catholic, Lutheran, Methodist, Unitarian, Congregational, Baptist, Episcopal, Presbyterian, Church of Christ, United Church of Christ, Reformed Church of Christ, Mormon, Quaker, Shaker, Greek Othodox, Russian Orthodox, Christian Science…the list seemed endless. It seemed like there were more different versions of Christianity in America than there were non-Christian religions around the rest of the world (Islam, Judaism, Buddhism, Hinduism, Taoism, Bahai, Shinto, Confucianism, etc.). Later, I learned that those other religions also had many different versions (Orthodox Judiasm, Ultra-orthodox Judiasm, Hasidic Judiasm, Reformed Judiasm, Sunni Muslim, Shia Muslim, etc.), so Christianity is not unique in that respect.

Meanwhile, Christians were fond of telling me that the Bible was written by God and, thus, was both perfect and complete. Naturally, this made no sense to me given the cornucopia of churches. If the Bible was perfect and complete, then why didn’t all Christians understand it the same way? Didn’t God know how to write clearly? More importantly, why were there so many different kinds of churches and what were their actual differences? To my immense frustration, churches of different denominations didn’t have signs out front explaining how they differed from the other churches down the street.

Only recently have I learned some answers to these questions. First, it turns out that the number of different versions of Christianity and other religions that I can name are only the tip of …