Religion (traditional and organized) is an idea that derived its origin from human mind. The creation of religion by man was made possible by the use of two basic instincts of human - imagination and conceptualization.

The primitive man generated - mental - images (imagination) of a "probable super being", as the one behind the awe inducing natural phenomena, they had no means of explaining the causes. This process evolved into - traditional religions.

The modern man, conceived and actualized (conceptualization), the organization of the traditional religious ideas into a body of knowledge - theology. The very foundation of organized religions.

Religious ideologies, created the only known vicious cycle in human experience: myth - horror - fear - hatred - conflict - war - pain - needless death.

Religion created this evil via the: in-group/out-group system of classifying human beings.

You're either an in-group or out-group member of any religious group.

An in-group member of a particular religion, perceives a fellow human beings, who is an out-group, according to how his religion has conditioned his mind to perceive human beings.

If his religion says an out-group person is a sinner, enemy, infidel, condemned, hopeless, demonic, foolish, lost and going to hell, so he will perceive his fellow human being. No matter the good moral standing, as long as the fellow is an out-group person, the perception will forever not change.

This is the reason why a Muslim who converts to Christianity, can be killed by his own biological father. And will feel no pain doing it, rather he will be glad he had fulfilled his religious duty. The Same way a Christian father will treat his son who became an Atheist, as an outcast and demon possessed.

Because religion is made of the fabric, of in-group and out-group system, anyone wearing the garment of religious beliefs on his mind, CAN'T BE TOLERANT of divergent and opposing ideologies/humans.