In Buddhism, there aren't any commandments, per se. There are the five precepts, which are more like guidelines. See, every action has its consequences, and instead of being punished by an omniscient deity, if you fuck up, you'll have to pay for it in some way. If you put your hand on a hot stove, you'll burn yourself. Same concept. No God involved in the hot stove, just physics and biology.

Anyway, the first precept is translated as "refraining from destroying living creatures." This is the concept of ahimsa, or not harming. The Buddha said:

There is the case where a disciple of the noble ones, abandoning the taking of life, abstains from taking life. In doing so, he gives freedom from danger, freedom from animosity, freedom from oppression to limitless numbers of beings. In giving freedom from danger, freedom from animosity, freedom from oppression to limitless numbers of beings, he gains a share in limitless freedom from danger, freedom from animosity, and freedom from oppression.

So, when you avoid taking life, fear and hatred subside. It's just a natural consequence, like the hand and hot stove. This extends from killing people, which most of us agree is usually wrong, to killing the mosquito that just bit you. Try, for a week, respecting a bug as you would a person. You will actually feel your suffering diminish.

Ahimsa is not just about not killing, though. Gandhi said:

Literally speaking, ahimsa means non-violence towards life but it has much higher meaning. It means that you may not offend anybody; you may not harbor uncharitable thought, even in connection with those whom you consider your enemies. To one who follows this doctrine, there are no enemies.

Ahimsa or non-injury, of course, implies non-killing. But, non-injury is not merely non-killing. In its comprehensive meaning, ahimsa or non-injury means entire abstinence from causing any pain or harm whatsoever to any living creature, either by thought, word, or deed. Non-injury requires a harmless mind, mouth, and hand.

For most of us, it's pretty easy to avoid inflicting violence on another. We don't go around hitting people (at least, non-consensually). But what many of us fail to remember is that WE are also "living creatures." And we do far more violence to ourselves than anyone else does. I'm not talking about the obvious, like smoking, drinking, and overeating. I mean that little voice in your head that tells you you're no good, that you just made a bad decision, that you should be farther ahead in life, that you can't do anything right. That's the most dangerous violence of all, because it causes all of the other forms of violence. A person who is completely at peace with themselves does not fight others.Anyway, this is something I'm working on, on a daily basis. Every time a negative thought comes up, it leads to a split in my mind. A miniature civil war. "You shouldn't feel that way." That internal violence can spill out into the rest of my life if it's not quickly contained. And so I raise the white flag, and stop fighting myself. This doesn't imply "doing whatever I feel like." It's acknowledging that sometimes I have selfish thoughts, sometimes I'm angry, sometimes I'm jealous, etc., and not immediately trying to bash those thoughts down with a baseball bat. The anger will subside. It always does. What's important is not fighting it or fueling it.