Is Christianity the Worlds Largest Religion?

We constantly hear that Christianity is the world's largest religion with 2 to 2.2 billion adherents.  But did you know that in order to get those numbers, you have to lump Catholics with Protestants, and even Mormons into the equation?   Why is it that predominately western statisticians feel free to lump all of the western religions into one grand number, but not do the same for eastern religions?

Many religious experts point out that Hinduism and Buddhism are both Indian religions, and could be compared to Catholics and Protestants.  Like Catholicism,  Hindu's are full of iconography and worship multiple religious heroes and deities, while both Protestants and Buddhists tend to keep things a bit more simple and concentrate on only the top level figures in their belief system. 

So why is it that when compiling numbers for Western religions, statisticians feel it is fine to lump all Western religions into one grand number, but not for Eastern religions? Could it simply be Western bias, as they don’t want to acknowledge the real numbers?

Let's take a look at the four biggest world religions in the way the numbers are currently presented by Western biased statisticians:

  • Christianity                 2.2 Billion        
  • Islam                             1.6 Billion        
  • Hinduism                     1.1 Billion        
  • Buddhism                    1.5 Billion        

What numbers do we see if we treat Hinduism and Buddhism (the Indian religions) in the same manner that Christianity (Catholic and Protestant) is treated?

  • Indian Religions          2.6 Billion
  • Christianity                  2.2 Billion        
  • Islam                              1.6 Billion        

Now, let's do the opposite and split Christianity and Islam apart in the same way they have split the Indian religions apart.  When we do this, you get the following:

  • Buddhism                    1.5 Billion
  • Sunni                            1.2 Billion
  • Catholic                        1.2 Billion
  • Hinduism                     1.1 Billion        
  • Protestantism              0.48 Billion
  • Shia                                0.40 Billion
  • Eastern Orthodox       0.30 Billion

So, what is the answer to our question?  Is Christianity the world's largest religion?  The answer is that it is only the biggest if you unfairly lump all of the Western religions into one pile and compare them against the Eastern religions in separate piles.  If you are going to lump all of the western religions into one big pile then you need to do the same with the eastern religions.  It is simply inaccurate to pile all of the western religions in to one grand number, and then compare it against the eastern regions broken apart in to separate numbers.

In short, the idea that Christianity is the world's largest religion is a Western biased view.


Note1: There are currently more than 33,000 known variants within the "Protestant" belief system, including the American religions (Mormons, Seventh Day Adventists, and Jehovah's Witnesses). 

Note2: Jewish adherents total between 0.009 to 0.014 Billion based on varying sources.  Coincidentally, the three American religions combined have similar numbers.