Hatred is act of evil, people are evil and is not only you this thing baffles.
And the reason is that people have the spirit of selfishness and lovely of money.
But you the holy book also said the heart of a man is full of evil, so it is difficult for some to love others.
because don't know that is good love and you know if someone is illiterate he or she will behavior anyhow and to get over this, is only God that can us.