what is the biggest religion in the world?why do you say so

Christianity is the largest religion by far being 50% larger than Islam all the best urban

My guess would have been Catholic religion. I don't have proof I'm right and I don't really have an explanation as to why I think this, I just think the Catholic religion is the biggest.

Not to sure on that I would think Roman Catholic for the send out lots of missinarys and have for 100s of years.

hi annji There are only 2 main religion in the whole world which belives in "converting" that is Christianity and Islam ... One of this religion will concure the world .. But do not forget the existance of other religion which has sustained and remained in this earth for as long as human creation .. this religions do not belive in "converting" others into their religon so they will only remain in the same group of people and not travel far .. chees

According to Major Religious Groups from Wikipedia, CHRISTIANITY is 33% of world population that is 1.9 Billion taken from Encyclopædia Britannica survey in 2005. Islam (20%), Hinduism (13%), Chinese folk religion (6.3%) or Buddhism (5.9%) The irreligious and atheists make up about 14%, and about 4% follow indigenous tribal religions. So the answer to your question is CHRISTIANITY is the Largest Religion in the World. JESUS is the ONLY WAY, It's the Fact! Whether the World accept it or Not. He is the WAY! God Bless!

No matter what the worlds says, Religion doesn't bring anyone to HEAVEN not even Christianity but JESUS does. He's the Only Way to HEAVEN. That's something that unbelievers don't agree but that's not a BIG DEAL. Only Faith connect us with God. God Bless You annjilena.

I think the world would be a better place if religions were not so important. I find that religions cause the biggest fight and confusion among people, after politics. Cheers!!