As a Christian should I be helping my fellow man even though they may be taking advantage. I have just read in the bible that if someone slaps you its good to offer the other cheek. Does this apply if you are being used? Should one continue to look after the person who is using you for the sake of peace? Does anyone know.
It is difficult to carry on giving when you give to a person who is totally taking you for granted, in the same way that it is difficult to forgive someone who is not in the least sorry. Yet this is part of the Christian life and you can do both things, giving and forgiving, in the sure knowledge that God always gives and forgives more than you ever could.
A guy called Rob Bell did an interesting sermon on this passage, looking at it with reference to historical context. He also included it in his We are the Peacemakers tour. He also talked about giving your coat, walking a mile etc in relation to the above. You can find previous sermons at Marshill.org.
Matthew 10:16 "I am sending you out like sheep among wolves. Therefore be as shrewd as snakes and as innocent as doves."
I would take that to mean that, though Jesus was sending out the disciples to help people, he did not expect them to be completely naive about what they would encounte.
You can also consider whether in the long run you are genuinely "helping" a person by allowing them to behave unjustly towards you - sometimes it is better for a person to be challenged about their behaviour and so encouraged to change.
So, I don't believe that to be a good Christian you have to be a doormat when you are reasonably sure you're being taken advantage of - you can also be a good Christian by making them aware that their behaviour is unacceptable, and that you cannot in good conscience continue.