Not only do some live on garbage dumps but there are those areas where the sewage from their homes are under and around the homes in open ditches and will drain off into their rivers (usually their only water supply). When disease hits it runs rampant because of such conditions.
It is disgusting to me that some so called Christians live in million dollar homes and own numerous vehicles while they know of these conditions of others.
Yes, this is a truly sad situation and goes against our Lord's teachings......Often the people with the least amount of money give the most to these types of poor people. I try to help native missions through Christian Aid....besides evangelizing, they also help the people living in dire conditions, and also run orphanages, training for former prostitutes, etc. Sometimes former Muslims are denied access to drinking wells in the villages.....the native missionaries help by boring wells for them, and the Christians let everyone use their wells, often leading to people accepting Christ as their Savior.
If every professing Christian would help the poor even with a small amount, it would all add up and mean alot. Of course, like you say, the ones with great wealth should help more!!