FAITH, n. Belief without evidence in what is told by one who speaks without knowledge, of things without parallel. (Ambrose Bierce - The Devil's Dictionary)
Those who profess a belief in god in some form or another are beyond persuasion on that matter. Even if the scientific and philosophical evidence were presented to them so that they could understand it, they would still rebel against reason and evidence because religious belief is essential to their psychological well-being - so much so that they could not abandon it. Perhaps if they were very young they might listen to reason, but when there has been time for indoctrination and parental authority has had it's way with them, then at that time they are so emotionally charged that they simply cannot and will not think rationally or objectively about giving up religion in favor of reason. They are so absorbed by their faith, so resolute, so dependent on their belief being true that they simply cannot relinquish those irrational mythopoeic religious ideas.
I'm certain too that psychologically it is probably helpful and healthful for them to believe - to surrender to their faith. Those people, as I have stated herein will never be persuaded - nor is that my intent. I do however intend to oppose irrationality and if their religion gets in the way of truth and reason it will be challenged on those grounds just as I believe it is necessary to challenge any bad ideas anywhere which ultimately causes harm and death and destruction and/or justified and blessed by religions.
Those who believe in belief will condemn my sacrilege and intolerance for unreasonable ideologies as heresy, impiety, immorality and all the other obscurantist smokescreens used by religionists from the time they were invented to today when George W. Bush receives his messages to kill bad Iraqis from his god.
Killing is pretty well established as a trait which may be inherited from our reptile and mammallian ancestors and embedded in our primate brains.
Male gorillas also kill young primates.
Writer/scientist Matt Ridley says this about infanticide:
"Infanticide is common among gorillas, as it is among many primates. A bachelor male infiltrates a harem, grabs a baby, and kills it. This has two effects on the baby's mother (apart from causing her great, though transient, distress): first, by halting her lactation it brings her back into estrus; second, it persuades her that she needs a new harem master who is better at protecting her babies. And who better to choose than the raider? So she leaves her mate and marries her baby's killer. Infanticide brings genetic rewards to males, who thereby become more fecund ancestors than males that do not kill babies; hence most modern gorillas are descended from killers. Infanticide is a natural instinct in male gorillas." (Ridley)
If we think that this search for God is a vain search, and that there is no reality to be discovered, ... then the history of religion becomes a study of the aberrations of the human mind. - (Cyril Bailey - The Greek Atomists and Epicurus)
Religion is the sigh of the oppressed creature, the feeling of a heartless world, and the soul of soulless circumstances. It is the opium of the people. (Karl Marx - "Towards a Critique of Hegel's Philosophy of Right")
Do our primate relatives have more fun? There is some debate about who we resemble more, bonobos, which were thought to be pigmy chimpanzees but we now know they are a separate species - or do we resemble chimpanees more. We are 98% genetically similar. There are big differences, physically and in other ways, in the 2% that is not similar.
Adult male gorillas weigh about twice as much as a female. That is because of the advantages in owning a harem of females so a larger male can keep other gorillas at bay. But chimpanzees don't compete and sex with the females is shared. There is an alpha who takes more sexual favors but he doesn't monopolize the females and the others also take their turn. Since there is less competition for a troop of females with chimpanzees there is no evolutionary pressure to be larger and besides it is a benefit for climbing trees not to be so big. And they have a lot of sex but bonobos do it even more. Since there is so much sex the sperm does most of the competing and male chimpanzees consequently have big balls. They ejaculate often and in big amounts . Their testicles are very large, which is necessary for their prodigious stamina for sex and relative to body weight their testicles are 16 times greater than a gorilla's testicles. And a male chimpanzee also has sex more often, to be precise about 100 times more often than a male gorilla.
Relative to body weight a human testicle is nearly five times as large as a gorilla's testicles but only 1/3rd the size of a chimpanzee's testicles. Maybe we should be having more fun by having more sex like the bonobos and chimpanzees -- and less time for war.