IN both of the previous chapters, Paul pointed toward our responsibility to work diligently (1:11 & 2:17) in the light of Christ's coming (3:5). In this closing chapter, he focuses almost exclusively on the importance of this principle. In fact, for those of us who tend to be workaholics, this should probably be our most favorite chapter in the whole Bible.
First of all, in verse 7 - 9, we see that Paul and his companions set a wonderful example of diligence when they were ministering in Thessalonica. By Paul's own testimony, we know that they worked "night and day" in that city while they were there (Acts 17). On top of that, Paul categorically commended hard work & condemned laziness among the believers in Thessalonica (vs. 10-12). That particular section seems to be aimed at plain physical labor. In other words, every able-bodied man should earn his own way. The principle seems to work like this: if a man in the church is able to work, but is simply unwilling to do so, then he is unworthy of charity and should receive no aid from the church. In this sense, help should go to those who can't help themselves, and to those who are trying to help themselves. It should not go to those who can but won't.