Hatred is an attitude of anger when a love is lost.
Hatred is an emotion that branches out from sadness depending on the situation.
In many cases of revenge in the Edo period a person felt hatred towards his or her parent's enemy. The person whose family was killed hates the culprit. Hatred has an extreme intensity that exceeds anger. Hatred makes people take revenge. Out of all the emotions hatred is the most dangerous.
The difference between hatred and anger is that hatred involves love, and also anger is a threat whereas hatred an attack.
Hatred is an emotion that one feels towards what causes one to lose an object of love. This is originally an emotion directed towards other humans, but can be directed towards other creatures or natural phenomenon if the object is personified. It is possible to hate earthquakes for example if one's child dies in an earthquake.
There is an inclination for believers of different religions to hate each other. The gods of a religion is given love, which is altruistic behavior without compensation. Many religions deny other gods from other religions. Since denial is the same as an attack against and object of love, so people easily hate believers of other religions.
Love has the power to maintain families or groups. Hatred developed as a punishment for acts which lead to a group's destruction. Hatred punishes the person who doesn't respect another's love.
However, the actual carrying out of acts of hatred is replaced by laws, so acts of hatred are a breach of the law]. In modern society the law has the same effect as hatred for everyone, so we must stop acts of hatred.
Hatred may be peculiar to humans. A female gorilla will sometimes mate with the male who killed her infant. War and the killing of infants among chimpanzees has been recorded but there are no cases of revenge. Based on this gorillas and chimpanzees may not feel hatred.