Sometimes, it is difficult for us to do the right thing. It may seem that something gets in the way each time we try to do right. However, Scripture encourages us to do good, regardless of our situation.
Paul was writing to the Thessalonians. A portion of his second epistle to this group of Christians was spent encouraging them to do good. The context of this passage makes it clear that Paul was talking about physical work. That is, the good that the Thessalonians were to do was not merely in word only, but in deed. They were to live it out, not merely speak it.
It is the same for all of us today. If we call ourselves Christians, we are to live a lifestyle that backs what we say. We are to practice what we preach. God is good, and to do works that are truly good we must imitate Christ. When we do this, others will see it, and God may do a work in another person's life because of the lifestyle that we live.