it's not necessary man cguro that you need religion, as long as your heart is open
to God..
In many ways we don't since much religion is merely man's ideas about God or gods and so unnecessary. Much religion (in Christianity at least) is totally unnecessary in terms of what God Himself regards as essential., and in terms of benefit to those who practice it.
Real religion involves knowing the true and living God who 'does not dwell in temples made with hands' and so is unknowable from the perspective of any religious practice we can create ourselves. Thankfully God has appeared in history and spoken and dealt with people and told us about Himself, so we can both know about Him and know Him if we want to since He has given His light to every man.
So, to put it simply, we don't need religion, we need reality.
WikiAnswers - Why do we need religion