3 Answers

Because religion is all about money, power and control. Men like money, power and control so men create religions. Religion is good business. There's a lot of money to be made in running a religion. Darkness, depression, rituals all help to control the follower. There's even more money to be made in a religion like that. People gift all that they own to the church as the price to pay to escape all the darkness. 

I don't know what the scientific  explanation is, but I think that the reason may be that religion is sort of a bonding agent. It encourages people to form groups with common purposes and goals. Its a cohesive force that contributes to a strong society, but also encourages division when it comes to others beliefs.  There may be some sort of genetic or biological element involved that creates the urge for religion to  answer the big questions. Morality and ethics as well as other things.

well many people are different christians there are catholic, lutheran..... and so on so on i'm a christian i'm lutheran.

Colleen

And you call yourself pregnant101.... Does this mean you teach people how to get pregnant or how not to get pregnant as 101 is used to represent a classroom?
This question was about religions, all religions, not just the Christian ones to which there truly are far too many of those. What about the rest of them? What is their purpose?