Patiently Exhort and Encourage
1Thess 5:14 And we urge you, brothers, warn those who are idle, encourage the timid, help the weak, be patient with everyone.
Apparently idleness was a problem among the Thessalonian Christians (too much socializing), which he mentioned also in the previous chapter (1Thess 4:11), and he mentions again in his second letter saying, “We hear that some among you are idle. They are not busy; they are busybodies. Such people we command and urge in the Lord Jesus Christ to settle down and earn the bread they eat.”2Thess 3:11,12
Realize of course that you shouldn't deal with every issue the same way. Some people need "a kick in the butt". Commanding, urging, warning, these are the kind of ways to deal with idleness. But there are also those who just need some encouragement, and for them it may not be appropriate (and may in fact be counter-productive) to treat them the same as the idle. (Throwing the timid into the water to teach them to swim may just make them more afraid of water) Don't be overbearing with the weak. And give people time to change. Sanctification is a process, not an event.
The Berean Christian Bible Study Resources