We should not tire of doing good, but instead, we should do good to everyone, especially to believers.

Galatians 6:7-10

7 You should not deceive yourselves. Remember that God is never outwitted {no one ever fools God}. Just like a farmer will reap exactly the kind of crop that he plants [MET], God will reward people according to what they have done [MET]. 8 God will punish eternally those who do what their self-directed natures urge them to do. But those who please God’s Spirit will live forever with God because of what God’s Spirit does for them. 9 But we should not ◄tire of/become discouraged while► doing what pleases God, because eventually, at the time that God has determined, we will receive a reward [MET], if we do not stop doing the good things that we have been doing. 10 So, whenever we have opportunities, we should do what is good to all people. But especially we should do what is good to all our fellow believers.