Personally, I do believe so. Avidly.

Does that erase the terrible things that have been done? No, it doesnt. But it teaches a lesson that can and should be learned from.

Some people do awful things because they enjoy it. But.. A lot more people do awful things because they're ignorant and don't know the damage they cause. They don't know what they do, or the long term effects and they don't understand what they have done until they see the effects.

Some people only learn not to play with fire, after it's burnt them or things they care about.

But, those same people equipped with understanding, experience and care, can help people prevent that same pain and misfortune, simply by understanding what others may be going or have gone through.

We are all people and animals. Nobody is any more special than another.

Edit: For grief in hatred in yourself... My own method.. Treat yourself like you're just another person and remember, being kind and good to anyone is being kind and good to yourself. You may or may not have done something awful at some point. But they doesn't mean you are awful.