This is a well-balanced and helpful word from Tim Keller in his book Ministries of Mercy:
Often books and speakers tell Christians that they should help the needy because they have so much. That is, of course, quite true. Common sense tells us that, if human beings are to live together on the planet, there should be a constant sharing of resources. So when the statistics are brought out to show Americans how much of the world’s resources we use, it creates (rightly) a sense of concern for those with less than ourselves.
But this approach is very limited in its motivating power. Ultimately it produces guilt. It says, “How selfish you are to eat steak and drive two cars when the rest of the world is starving!” This creates great emotional conflicts in the hearts of Christians who hear such arguing. We feel guilty, but all sorts of defense mechanisms are engaged. “Can I help it if I was born in this country? How will it really help anyone if I stop driving two cars? Don’t I have a right to enjoy the fruits of my labor?” Soon, with an anxious weariness, we turn away from books or speakers who simply make us feel guilty about the needy.
The Bible does not use the guilt-producing motivation, yet it powerfully argues for the ministry of mercy. In 2 Corinthians 8:2-3, Paul tells us that the Macedonian Christians gave generously to the Jerusalem famine victims. He notes that “out of the most severe trial, their overflowing joy and their extreme poverty welled up in rich generosity” (v. 2). The Macedonians were not of a higher social class than the needy in Jerusalem. They apparently were going through terrible trials of their own. What, then, was the dynamic that moved them to give? “Their overflowing joy . . . “ (v. 2) and “they gave themselves first to the Lord” (v. 5). It was the Macedonian’s response to the self-emptying Lord. Their gifts were a response, not to a ratio of income levels, but to the gift of Christ!