And yet, that is exactly what God calls us to do - love our enemies, those who dislike or mistreat us. It is, in fact, the path to kingdom living. Listen to Matthew, "You have heard that it was said, ‘Love your neighbor and hate your enemy .’ But I tell you, love your enemies and pray for those who persecute you, that you may be children of your Father in heaven" (Matt 5:43-45).
This is the attribute that seperates us from the world. In verses 46-47, Matthew tells us that even the tax collectors and the pagans love and treat kindly those who love and treat them kindly. But we are called to "Be perfect, therefore, as your Heavenly Father is perfect" (v. 48), meaning to love even our enemies.
Jesus tells us in John 13:35, "By this they will know you are my disciples, by your love for one another." This love for one another has to include those Christians who have not been loving to you or the one with whom you are upset. Otherwise, it would not be a love that would distinguish us from everyone one else.
It is not always easy, but it is alway right to love others regardless of how loveable or how friendly they are or are not. It is a God thing to which He calls us and which qualifies us as His children.
Jus' Sayn.