Answer:
Christianity is the most followed religion coming in with around 32% of the population. (Around 2.2+ billion people)
Explanation:
As early as 1 AD, after Jesus was killed, is when this popular religious group began. This small group grew quickly through the Roman empire. Besides a few altercations in the process, it then went from the middle ages, spreading into northern Europe and then Russia. This is then followed along by many other areas of living and so on and so forth. Though, coming in second place is Islam, with a near 23%.
