When we see others with a greater need than ourselves we should at least make a start towards equality. Praise God for Christian organizations which are concerned about the crying needs of people around the world. We should give liberally to these organizations. Verse 15 guards against such thinking. Read that account of how God miraculously provided bread for His people, and it becomes clear that equality was accomplished on the basis of needs, not amount.
Communism aims for equality, but it is on the basis of the same amount for everyone.
Christian giving aims for equality on the basis of meeting needs. Verse 15 also teaches us something else in reference to giving towards equality. It is something we growing Christians must wrestle with and it is heavy. We must deal with our hoarding tendencies before the Lord. From these verses we see that Paul was not commanding them to give.