Crossing Cultures

Since day one here I have known that there would be some interesting situations in ministering cross culturally. I with that it just touched my culture to Brazilian culture, but it even goes further than that. I have seen also that it is difficult to reach different cultures of Brazil at the same time. Right now, the missionary house that we live in is in a condominium development where the upper class lives. We have an electric fence around us for safety and a guard at the only entrance and exit. We are very safe inside from the crime ridden neighborhood all too close by outside. There is a vila (or favela, which is a poor neighborhood) that is close by. Vilas are dangerous places to be.
I play soccer with kids from the vila every Sunday. I look forward to it and really enjoy it. I am also friends with a lot of them. If I see them on the street, they say, "eh Americano" and we give each other the thumbs up. Then I have fun with them on the soccer field.
I am also friends with a bunch of our neighbors. I talk to them every once in a while, have eaten with them, played soccer with them at their club, and even visited with them at their relative's house. It has been neat getting to know them and even try to reach them.
But where the culture difference lies is between the both. Those in my neighborhood don't want me to let my friends from the vila inside the gates. They don't trust them at all. So how do you minister to them in a way that is humble, even though they are basically prohibited from coming in your house? (A couple of them came in once, but I heard that was a bad idea from my neighbors). It is an interesting situation because I want to minister to both of them, but if I do too much, one will not allow me to minister to the other. I know Jesus ministered to both and that is what is right, but must I first revise the entire Brazilian culture of social levels?