Being a christian, it is required to love others and be a blessing to them and help them.
However, this is a self centered world. And most of the times people will just abuse your help and refer to you only when you are needed.
Throughout the years i noticed that most people keep their human relationship with you only limited to the Days where they need your help.
I started to believe that it is not "always" sane to help others. What do you think - based on the bible - is the limit where helping others must stop?
The thing is, even if you have a deep faith and would like to be a blessing to others, the selfishness of people at some point might make you not enjoy what you are doing anymore.
UPDATE: 5/29/2012
In addition the the great feedback below, i would like to share what i read today in the bible and which is related to my question
Matthew 5.6-10:
"Happy are those whose greatest desire is to do what God requires; God will satisfy them fully!"
"Happy are those who are merciful for to others; God will be merciful to them!"
"Happy are those who are persecuted because they do what God requires; the kingdom of heaven belongs to them!"
