It seems monotheism developed to bring down an ancient, corrupt, political/religious system. When civilizations first evolved they apparently felt a need to justify their existence in divine terms. Thus by the time of 3000 years ago in the Middle East, for instance, the belief was in a kingdom or empire that had "divine" justification. The king was a "Son of God" who ruled the kingdom or empire as a "Divine Shepherd" and was also required to perform religious ritual to maintain "Divine Favor" for the kingdom or empire. Of course, as you can imagine, this was probably accompanied by incredible levels of abuse that appear to have had good "staying" power.
Monotheism was probably the response by those hurt by or left out of this system. It essentially was an anti-religion of its day, designed to bring down the political/religious "establishment". (An anti-religion is a religion that seeks to diminish if not destroy all other religion) It eventually succeeded, partly by inventing a new concept, an evilly brilliant faith-based propaganda and war-making tool in its war with the "system". This, of course, was the punishing "hand of God". Ancient monotheists used this tool to help consolidate their hold on Palestine and probably used it against the Egyptians before being chased out. This tool is still being used today. The anti-religious/terrorist organization, Al Qaeda, for instance, is currently using it when they say that "God destroyed the World Trade Center". This tool allows monotheists to say that "God" is punishing the "evil-doers" when in fact it is they, themselves, who do the punishing in terrible and tragic terrorist acts.
So now, 3000 years later the head is finally biting the tail. We are witness to an incredible situation. Monotheism, an anti-religion of the past, is now the "establishment" for about one third of the world. It has grown large and has fragmented into large, mutually exclusive antagonistic parts. These various versions are now used to justify kingdoms, empires and countires and they are now often at the head of abusive political/religious systems. Horribly, as a result of the hellish and twisted contradiction monotheism now finds itself in (having been created in the first place to bring down state religion), it now is being driven to destroy itself! So now we see the phenomena of these various versions engaging in horrible and tragic wars with each other's "systems". Even worse, many monotheists are armed with nuclear or other terrible weapons of mass destruction! As a result, civilization and even our planet are facing an immense threat to their life. We owe it to ourselves and our potential descendents to short-circuit monotheism before it does what is now possible for it to do; to destroy everything!
Real hope and real ways out must be provided to counter monotheism's pernicious apocalypticism and its ugly secular step children, nazism, communism, ba'athism, etc. Two main things can and must be done: Space exploration and utilization must be dramatically increased (to provide ways out) and civilized countries must stand up and fight for freedom and liberty manifesting as constitutional republics as the only philosophy for government (to provide hope and to counter nihilism and cynicism).
You know, it would be so immensely tragic for us to let that ancient, violent, monotheistic "god" reach up through the centuries and swat everyone down now that humankind are on the verge of an epochal expansion into space.