The Greek verb kalopoieō (καλοποιέω) means to do good, to act in a morally excellent manner, or to do what is right. It is a compound of kalos (beautiful, good, morally excellent) + poieō (to do, make). It appears only once in the New Testament (2 Thessalonians 3:13), making it rare — but its single occurrence is instructive.
The rarity of kalopoieō makes its one New Testament use all the more striking. In 2 Thessalonians 3:13, Paul has just given strict instructions about dealing with idle believers who refuse to work. Then he adds: 'But as for you, brothers and sisters, never tire of doing what is good (kalopoiountes).' The command is set directly against the context of watching others fail — the temptation to stop doing good when others around you are shirking is real. Paul insists that the church's calling to persistent, beautiful goodness is not contingent on the conduct of others. Galatians 6:9 (using a related phrase) echoes this: 'Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up.'