Growth in our relationships does not happen automatically; growth takes effort. Hard work is required if broken relationships are to be rebuilt. In these two verses Paul simply encourages Christians to keep on working at building their relationships: Let us not become weary in doing good (v. 9). To say that Paul's emphasis on faith means that he was against works is obviously an inaccurate interpretation. Although he warned against relying on the works of the law as the basis of blessing (3:10-14), he clearly taught that true faith expresses itself through love (5:6) and in the hard work of serving one another (5:13) and carrying each other's burdens (6:2).

One of the greatest obstacles to rebuilding broken relationships is simply fatigue. We can easily lose heart and run out of strength when we come up against the same problems over and over again as we deal with others. Even Paul sounds discouraged when he talks about his efforts to rebuild his relationship with the Galatian believers: "I fear for you, that somehow I have wasted my efforts on you" (4:11). Paul recognized that fatigue and discouragement might cause Christians to throw in the servant's towel and quit. So he presents two incentives to keep us from giving up when we grow weary of serving others in love. First, he assures us of a reward for doing good: at the proper time we will reap a harvest if we do not give up (v. 9). Sometimes the harvest is experienced in this life. When we sow acts of love, we reap a harvest of love in return. When we give generously and sacrificially to the needs of others, we reap a harvest of gratitude as those needs are met. When we sow the seed of God's Word in needy lives, we experience the joy of response. But we must remember that reaping a harvest almost never happens on the same day as sowing the seed. We may not even see a harvest in this life from what we have sown. Nevertheless, we must never give up, because we know that at the proper time our Master will return and reward those who have been faithful servants.

Second, Paul motivates perseverance in service to one another by reminding us that we are part of a great family: Therefore, as we have opportunity, let us do good to all people, especially to those who belong to the family of believers (v. 10). Although there are no limits placed on the scope of our service to all people, our priority is certainly to serve the family of believers. Here Paul picks up a central theme of his letter. All believers are children of Abraham by faith in Christ, the seed of Abraham (3:6-29). All believers enjoy the full rights of the children of God (4:4-7). All believers are the true children of the free woman; the heavenly Jerusalem is our mother (4:21-31). These great truths about the family of believers should motivate us to keep on doing good to our brothers and sisters in Christ. We belong to one another in one family, since we belong to Christ.