From Simple/House Church Revolution book:
When someone enquired about visiting Mother Teresa to help with her work among the poor of India, she encouraged the person to find their own Calcutta. In other words, each of us must discover who it is that God has put on our heart to love and reach out to. This makes it personal and meaningful.
As we listen to God’s voice, we will begin to sense that we have a particular heart for a particular group, or several groups, of people. Jesus, in his human experience, was called to the people living in Israel. He knew his focus. In the same way, God has given a focus to each of us, and we will find great joy in our love-life towards others if we accept whom we are called to.
The most obvious focus for us may be those we are already living among: our family (church always begins at home), our extended family, our neighbors, our co-workers, and our friends. At the same time, we may have a particular concern for a nearby people group: homeless, youth, prisoners, children, elderly, etc. It may well be that God has put this group on our heart because we are specifically called to them. Finally, we may know the stirring for a people-group that does not live near us, i.e., the unreached of Africa or the inner city poor.
Knowing who we are called to and being willing to position our lives so that we can readily love those whom God has given us to love will allow us to begin expressing the passions and gifts that we were made for.