Love is something that is built. It is seeing the true neshama of a person. It is seeing the great heights that this person can achieve and reach to. You are at awe of his greatness. It is the ability to see the fire burning within him. You also love someone for who they are because that is how Hashem created him, with his own positive attributes. People also use the word love too often to really know what love means. We tend to use love with the way someone looks, does, wears, etc. We shouldn’t love someone just for their physical or materialistic qualities. We should love one for their chessed, love to others, and greatness.
When we see the evil soul of a rasha and what he does, then we hate it (Hitler). We hate that this person/nation has such an evil inclination and such evil actions. We hate that such a person could reach to such a low level and we don’t ever want to understand such a position. Therefore we reject it because it is alien to us.
I don’t like to believe that we hate others because of what he did to annoy you. You don’t really “hate” him. Deep down you really love him, but because he bothered you in some way (i.e. mean comment) then you hate that action/part of the person.
I think now day’s people use the word Hate too often and have lost the true meaning of the word.
“Just because I don’t like you, it doesn’t mean I hate you”.