I so agree with all who have raised the point that you do not need religion in order to lead a good honest and worthwhile life.
I also agree that, in the main, the thrust of most religions is towards just this.
However we cannot ignore the way that religions have been corrupted by those involved and have in many instances wrought immense damage both on a mass scale (the crusades, northern Ireland for example) and for individuals (persecution of gay people, demoting of women, personal guilt etc.).
Tolerance of people's beliefs is a huge problem, because, while we would all like to do that, there are practices within some religions that are hard to reconcile with a humanitarian approach to others: the ritual mutilation of baby boys in the name of religion completely appals me and I am at a loss as to why this is still legal in this country; burdening young children with the concept of original sin and the guilt that this carries; female genital mutilation; etc. etc.
I am fully aware that most Christian churches in this country are entirely benign and in many instances a force for good, but we cannot safely ignore the corruptibility of religion to individual ends, because the results are so dreadful.
The basic problem is that religion deals in fundamentals (why are we here? why do we die? what are we meant to be doing with our lives? etc) and if people think they have found the answers to these questions in their religion, it is very uncomfortable to also tolerate the idea that someone else has different answers. Dealing in fundamentals has a natural tendencey towards fundamentalism and herein lies the problem.