The belief in God has persistently led to war throughout the whole history of humanity. From the earliest of times in the Paleolithic period up to the very present, mankind has experienced countless armed conflicts that took place in the name of God. There have been more than a million wars over the last 100,000 years and practically all of them were directly or indirectly the result of religion.
There are two reasons for this situation.
Whether it is the most primitive religions of the Paleolithic period or the large ones of today, all creeds have always claimed that their particular God is omnipotent. Another common denominator of all religions is the claim that their God is the only true one.
With such a vision of things, a clash is inevitable. When two persons or two nations that venerate a different God come in contact, both are inevitably driven to try to impose their God on the other. The end result is conflict, which frequently escalates into bloodshed.
In the absolutist and irrational vision of the world of religious people, there is no room for compromise.
The second reason explaining the inherent violence of religions is what resides at their very core. Everything that happens in the world, according to them, is due to the will of God. For religious persons, whatever occurs, no matter how much suffering it brings on to millions, cannot be condemned because God is infallible. People must therefore resign to the whims of the Almighty and accept everything with resignation. That ultimately translates into a state of mental passivity and under those circumstances science cannot make any progress.
Religions however, not only indoctrinate people into passivity. They also impose a harsh repression on those who dare think scientifically, suppressing in such a way most of the remaining inventing inclinations of a population. The amount of intellectuals and scientists who through history were imprisoned, tortured, and murdered is almost as numerous as the stars in the Milky Way.
Since progress cannot be attained without science and technology, religions ineluctably condemn nations to poverty and when nations are poor they always turn violent. Poverty is such an atrocious and painful condition, that when a country endures it people inevitably resort to violence as an instinctive mechanism of survival.
Countless wars through history were the result of territorial disputes, ethnic differences or some other non-religious factor. However, it was the poverty of the parties involved what really pushed them into confrontation, and that was the result of religion. When people are indigent, minor things such as linguistic, ethnic, or cultural differences drive them to war.
As the biggest hindrance of progress, religion is without the slightest of doubts, the cause of all wars. History shows that there is nothing more pernicious for the well-being of society than religion.