The plight of the infidel.

How do we come to terms with the incomprehensible. Its incomprehensible that in this day and age we are being confronted by people who, raised in the UK, hate the country they grew up in and classify the people they grew with as infidels who need to be killed all in the name of a religious belief that is extremely  tenuous, given that much of the hatred is based on an earthly schism between the followers of The Prophet Mohamed 1500 years ago. The rift which grew between the Abu Bakr followers, the Sunni and the Ali followers, the Shia has dogged the Muslim religion for centuries.
That segment of Sunnis which represent the extremist faction ISIS, and its attempt to create an Islamic Caliphate in Syria and Iraq is a human political anomaly dressed up in a historical event regarding who would carry on the work of the Prophet on his death.
Hubris is the term which, down through the ages has dammed mankind's intentions.  If you add the enmity which is taught regarding the "other group", identifying all but "your own group" as the enemy, not even "your enemy" but, by twisted logic, "everyone" other than Abu Bakr's followers are "gods enemy" and deserve to die the infidels death.
How do we cope with such a tendentious bias for a raison d'etre that seems so alien.
How can we create a reasonable co-operative  attitude towards something which seems so over the top. How can religion have drowned common sense or our innate belief that it is of enormous importance to consider all of mankind as fellow human-beings.