It probably depends on how it's introduced and how the child responds.
My mom is agnostic and my dad was an atheist, so I wasn't introduced to any specific religion until I was 11 and went to a Christian camp with my friends. By that point I was already a loving, respectful, caring human being... so I certainly don't believe that religion is necessary to achieve that.
I was apparently at a very impressionable age when I went to the Christian camp, because it took me all of like a day to jump on board. I even signed this certificate declaring myself a Christian before leaving (which in hindsight makes me a bit uncomfortable). Anyway, I went home considering myself a Christian after only A WEEK there and wanted to go out and buy a Bible, crosses, etc. I think my parents' reaction to this taught me one of the biggest things I ever need to know about raising a child. They supported me, 100%. They talked to me about it, they bought me the Bible, they took an interest despite not being Christians themselves. They accepted my exploration of religion.
I actually considered myself a Christian for years, until I was about 16. My dad died shortly after I started questioning my faith and that pretty much signalled the end. I took religious studies in college, partook in Buddhist ceremonies and submerged myself in it while in Japan. I looked and learned and took the time to think about things. It's a huge part of who I am today and I am very, very thankful that my parents let me do it.
So, I plan on telling my kids about different religions when they're old enough. I plan on telling them they can choose and think for themselves. I think that being open and honest about religion helps raise kids. There's a lot I like about Buddhism and Christianity without identifying as either a Buddhist or a Christian. I understand how certain principles would be helpful in raising a child. But I think teaching them that ONE and only one is the correct religion is a hindrance.