But when you observe other species that are very similar to humans such as gorillas for example you realize that they are all peaceful and not violent collectively, no phenomena such as rape, stealing etc exist, so if that was the case wouldn't some gorillas be naturally violent as well?
By not violent in this context I mean that they show the bare minimum amount of violence which is needed for survival.
Violence, however, is preventable. Evidence shows strong relationships between levels of violence and potentially modifiable factors such as concentrated poverty, income and gender inequality, the harmful use of alcohol, and the absence of safe, stable, and nurturing relationships between children and parents. Scientific research shows that strategies addressing the underlying causes of violence can be effective in preventing violence. Examples of scientifically credible strategies to prevent violence include nurse home-visiting and parenting education to prevent child maltreatment; life skills training for children ages 6–18 years; school-based programmes to address gender norms and attitudes; reducing alcohol availability and misuse through enactment and enforcement of liquor licensing laws, taxation and pricing; reducing access to guns and knives; and promoting gender equality by, for instance, supporting the economic empowerment of women.
(Not that I necessarily agree with everything in that quote, seems biased to cram some agenda)
Gorillas may not rape or kill for fun, unlike their more evolved counterparts, but they will kill babies so that the mother will mate with them.
Most infanticides occur when infants' mothers are not accompanied by their group's mature male (usually because he has died). Infants in this situation are almost certain to be killed by unfamiliar males unless they are nearly weaned. Active defense of infants by females is ineffective, and females cannot avoid unfamiliar males for prolonged periods. In contrast, infanticide is rare — yet has been observed — in encounters between mature males. It is not associated with group takeovers and male eviction by extra-group males, unlike the case in many other mammals. Demographic constraints and reproductive competition limit the occurrence of defensive coalitions between males. These factors, plus the high risks associated with male/male aggression, inhibit the occurrence of group takeovers by male coalitions. Infanticide shortens interbirth intervals and results in a high probability that a female will mate with the infanticidal male.
Is this type of murder "necessary"? I have a feeling if you ask the infant the answer would be no. From the male gorillas point of view its all about ensuring the survival of his genetic line by mating with the mother of the baby gorilla he just killed. Granted you cant compare this to what humans do to each other on a daily basis but it is none the less an example of violence for selfish reasons and ones not related to survival but procreation.