Who is most Religious

Before writing anything further on this post I have to say something totally un-related. I just watched Amazing Race (India episode) and after watching this and previous episodes I would like to say, Rob is the worst and rude (badtameez) american I ever saw, this guy doesn't know how to behave and talk with others.

Finally today new Pop (265th) is elected, I saw the crowd waiting outside of Vatican (city). It was un-believable. Now-a-days Vatican city was getting most of the news media coverage in USA. Most of the religions in the world have at least one head leader (who leads to rest of the priests or clergy). I think Shankaracharya is such leader for Hindus, Dalai lama for Buddhist and same way there are leaders for Muslims, jews etc. I don't remember if I ever saw or heard such thing in this scale for other religious leaders. And this question just poped-up in my mind, who is the most religious community.

I conclude this post with two other question, why artificial birth control not allowed in christianity (Catholics). Based on their population I can say definetly they use some other method or way (natural) to control the birth. Then why not artificial, because at the end result is same and if it's killing of life or something then it happens either way. And last what stem cell research (Science) has to do with religion.

I would like to hear views from lonely planet's visitors, what they think?