Hatred is may things where it comes from etc... is different for many folks as well. However, I've personally never been one that could ever hold onto it. It always felt heavy to me, at the least the kind towards other people. Because it is a consuming force and not in a good way. It clouds and creates falsehoods within one's being. Much like many other emotions that linger and make us feel things that aren't there. Holding it in, is what makes it fester, wound more deeply. For, if it stays within one's heart and rots, it only causes more pain. Hatred only begets more hatred. It's a force that feeds itself by creating more of itself. Though that is hatred left unchecked it's extreme.
Most hatred that is removed only is temporarily as well, imo. It's only backburnered. Eventually it bubble up and out, coming to an explosive head. Hence why I don't believe in holding that stuff in. We've got too many emotions that when bottled within ourselves violently erupt. We has humans have so many things within us that jsut have the potential to get to a point they boil over. Hatred can easily become this in it's extreme. It can easily boild over and become something much uglier. It can create so many falsehoods in the mind of another and force them more or less into a position where this Hatred just feeds and grows and as it does, consumes more of them.
THough in some sense, it is healthy as well. Not in the consuming variety of course. One could say disliking something is a form of it, a mild one, but one nonetheless. In some regards it's a force that drives. It makes us do things, it's doing the right things that matter with it. Disliking how something oppresses another thing etc... the want to do something about that. Think of it as the good form of anger. anger if we see injustice in the world around us, anger compels us to act. ((in different ways for different people.)) It's more or less using your emotions as a tool, a platform to help understand the world around you, and not letting any single one consume all of your being. It's really just, give and take. Ebb and flow. We need these emotions these feeling because of we have them fro a reason. They teach us and help us grow. Some drive us to do. Others drive us to not act ((such as fear.)) for maybe good reasons. But, we must learn their ebb and their flow as well. There is a time for emotion, and there's a time for that to pass. And, it's learning this that is the key I suppose. It's definitely no easy task but... one that's important to learn I feel. It's different for every single person as well. For some of us, we need to feel some emotions longer, in our own alloted times. Others want to get them over with as soon as they can, etc... We as people jsut need to leanr how, why, and everything else about our emotions so that we can better understand ourselves. Hatred, is one of thsoe things. It's jsut understanding it's importance and the times it does matter, and when it should be let go of. Most hatred should fall to the wayside, and be done away with. But, it sometimes holds valuable lessons, as every aspect of life does if you look in the right places.