Short Answer: Your questions seems premised on the idea that religion in particular causes violence. There is no evidence to that effect.
It's better to ask if any group of humans will, given the power to do so, never commit violence against other groups. Evolutionary theory says no. If we believe we can benefit from from violence we will use it. We don't need religion to justify warfare, we can always find an excuse. Religion likely stops more wars than it enables.
The key factor in violence is a group of humans acquiring the ability to profitably commit violence against others. It is the capacity to profit from violence that comes first. All rationalizations on the morality of the violence, including religious ones, come later.
In the case of large organized religions, this usually means become allied with some state and becoming an established religion. When the religion becomes an arm of the state, the potential for violence is very high.
Religion disconnected from the state cause little violence and the more disconnected from the state, the less violence they cause.
Outlaw sects hiding in the shadows of the state rarely cause violence. Christianity existed peacefully for over 300 years in the Roman Empire. It was not until it became a state religion that we see begin to be used to rationalize violence. The same pattern occurred in Buddhism.
Conversely, Islam has militarism built into its core. Unlike, Jesus and Buddha, Mohamed was a military leader (and a very good one) yet during the Islamic golden age, Islamic polities were beacons of learning, trade, tolerance and in many wide areas, extremely peaceful compared to their contemporaries. Even, though many interpretations of the Koran seem to require Muslims to war constantly against the infidels, historically they only do so when war confer some material advantage.
Clearly, the effects of religion itself in promoting warfare if fairly minor and is overshadowed by more materialistic concerns and motives.
Religion is not especially violent. Objectively, in the last two hundred years, materialist atheist have proven much more brutal, bloody and warlike than the religious in the same time period. Every atheist dominated polity since the French Revolution as turned instantly muderolus and warring.
The 20th century is largely the story of the war against murderous states with ideologies founded in materialistic atheism, who adopted notionally secular ideologies but which functioned as religions in terms of their absolutism. It appears that if people do away with a supernatural religion, they just reinvent the same functional structure using a made up materialistic explanation. We get the worst of religion with none of its built in moral restraint.
I would also note that the idea that "religions cause wars" is fallacious. People fight whomever is nearest and the vast majority of wars are fought between coreligionist. It's impossible to point to a war which was caused purely or even primarily by religion. Instead, all notionally "religious wars" arise from a complex combinations of dynastic ambitions, lust for wealth by conquest, counter-attacks etc which are just wrapped up into religion.
Its also common for combatants to jump across religious lines in search of allies. France famously funded the Ottoman Empires attacks against the Holy Roman Empire to split its attention between the Ottomans and the rest of Europe. France also, though a Catholic country, funded the Protestants, particularly Gustave Aldophus of Sweden in the 30 years war.
Cromwell fought the Protestant Dutch, then allied with Catholic France against Catholic Spain.
The Christians dominated liberal-democracies allied with the atheist Soviets during WWII. (Even though the Soviets had destroyed the churches in their own domain and declared they would do the same every where when they conquered the world as "historical inevitability said they would.)
Religion relates to fostering war only in that makes people more militarily effective. The function of religion is to foster cooperation between co-religionist. Military success is all about internal cohesion and cooperation. The more internally cohesive and cooperative a religion makes a people, the more militarily effective it makes them. Historically, militarily effective peoples have also been deeply religious e.g. Sparta, Rome.
Historically, "religious wars" have just been the means to increase cooperation across political boundaries in order to fight larger wars.
The Famous Crusades where just a counterattack against the massive conquest of Christians lands the Islam's had carried out over the prior 400 years (itself land grabs more than Jihads.) Muslims and Christians spent most of their time fighting each other but by evoking religion, The Popes and the Mediterranean kingdoms, hoped to push the Muslims back or distract. They choose the holy land not only for its symbolic significance but because it was accessible by sea and not very mountainous.
Ventians provided the transport even though they made most of their money trading with the levant.
The Muslims at the time where busy fighting each other and pretty much ignored the invasion for two centuries as the Holy Land was not otherwise significant territory. When Saladin finally wiped out enough Muslim competitors to establish a broad kingdom, he just brushed the "Frankish Kingdoms" aside, even though they were nearly two centuries old at that time.
Historical evidence shows that the world's major religions suppress warfare internally strong textby making cooperation the ideal moral behavior. As religions become larger and larger, the rate of human on human violence drops.
The upshot is that is seems impossible for any group of humans for justifying war if the payoff seems high enough. We'll find a rationalization and cram it into whatever religion, ideology, philosophy or science we have on hand to justify our war.