Why don't we love our neighbors?

"I like your Christ, I do not like your Christians. Your Christians are so unlike your Christ." Mahatma Gandhi

If Christians are called to Love your neighbor, why is there so much hate in the world?

Mark 12:28-33 tells us:

28 And one of the scribes came, and having heard them reasoning together, and perceiving that he had answered them well, asked him, Which is the first commandment of all?
29 And Jesus answered him, The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord:
30 And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment.
31 And the second is like, namely this, Thou shalt love thy neighbour as thyself. There is none other commandment greater than these.
32 And the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he:
33 And to love him with all the heart, and with all the understanding, and with all the soul, and with all the strength, and to love his neighbour as himself, is more than all whole burnt offerings and sacrifices.

If the story of the good Samaritan is an indication of who our neighbor is, then he is anyone and everyone around us. 

My issue is not with those who claim not to believe in God, it is with those who say they are Christians and practice hate.  If we want to win souls for Christ, how can we be so judgemental and unloving?  I have heard it said many times that you can win someone over better with honey than you can with vinegar.  Do we just not care?  Are we so absorbed in what we consider to be morally right that we can't be a light?

I understand the concept of sin.  We are all sinners.  Are some sins worse than others?  Probably so.  But how will we win the sinner over if all we do is criticize and condemn?  Is a person addicted to painkillers less of a sinner than the woman who dances in a nightclub to put food on her table?  If we don't show compassion, we have already lost any chance of winning them over.  Why would someone want to be a Christian if we judge and condemn?  If we love with neighborly love, a door just might open.