Paul urges all brothers and sisters to “carry each other’s burdens” (Gal. 6:2), or troubles. As a Body of believers, we should help our members when one is weak. We can experience this through fellowshipping with one another and developing knowledge of one another; developing a knowledge of our gifts, strengths and weaknesses. The point of Paul’s remarks here is that while we are individual parts comprising one larger entity (the Church), no one person can be totally independent. Paul is remarking on their ignorance that they can accomplish salvation or righteousness by themselves.
As members of the adopted Body, they must learn to work together – carrying their own load as purposed, but helping one another for the growth of the Church.