Mark 2:16-17 King James Version (KJV)
And when the scribes and Pharisees saw him eat with publicans and sinners, they said unto his disciples, How is it that he eateth and drinketh with publicans and sinners?  When Jesus heard it, he saith unto them, They that are whole have no need of the physician, but they that are sick: I came not to call the righteous, but sinners to repentance.

  A lot of people believe that they are too far gone for Christ to save them, Some Christians even seem to believe this of certain people, but he came for the Demon possessed, the thief on the cross, tax collectors, Saul the murderer and persecutor of Christians. I don’t care what you have done, you are not too evil for Christ to redeem.
Christians, sometimes you have to back away from people for your safety or even your sanity, but even those that you fear so much that you want to run when you see them can be redeemed by Christ. They still have to pay an earthly cost for their sin, but Christ blood can even cleanse them. If you can not bring yourself to witness to them, pray for them.