Refrain from anger and turn from wrath;
do not fret—it leads only to evil.
For those who are evil will be destroyed,
but those who hope in the Lord will inherit the land.
There is nothing easier than letting oneself get in a stew over the supposed and actual lack of love in other people. This is particularly true when one ought to expect better. At the same time we have to be aware of the accuser of the brothers and sisters, the evil one, Satan, who not only accuses them day and night before God, but to each other, so that we might be wise and not fall prey to his schemes.
Psalm 37 itself is likely talking more about those who are enemies, or at least are not friends, namely the rich, who may seem to be doing well while the righteous are suffering perhaps even by their hands. The idea in the psalm that life is unfair and one is agitated and upset, even angry at God over it (see Peter C. Craigie, Word Biblical Commentary, Psalms 1-50).
To fret has the idea of being rubbed back and forth to the point of agitation where something in particular is either on one’s mind almost all the time, or is easily recalled. And it seems akin to not only turning into anger against God, but also to grumbling against him, cardinal sins of God’s people in the old covenant which his people in the new covenant are warned against.
I have to reject such thoughts by ongoing prayer, and from that, replacing my thoughts, words and actions with those which are counter to the grievance at hand, even while I continue to bring all my cares and concerns to God. The Lord does not look kindly on us judging others, particularly those who are our brothers and sisters in him. We are all one family in Jesus, and we’re accountable to God and we ought to be accountable to each other, to the church to love one another not only by profession, but in tangible, sacrificial ways.
We are called to judge sin, what is displeasing to God in ourselves, to deal with it ruthlessly. If we don’t, sin will do us in. We are told that fretting leads only to evil doing. And that evil doers will be cut off from the land, or from God’s blessing. Just as anger or lust can lead to an evil act, and certainly affect our character for ill, so fretting as in being agitated and in anger and worry can make us think and act in ways that do not indicate trust and obedience and devotion to God.
And so I need to learn better to put aside all fretting and worry. Instead to do what Psalm 37 tells us to do (read the entire Psalm, click the link above). Not to be bothered by what can be so bothersome, but trusting in the Lord for his goodness and blessing so that we might be a blessing in and through Jesus.