concerning mutual love
Above all, keep fervent in your love for one another, because love covers a multitude of sins. Be hospitable to one another without complaint. (4:8–9)
Mutual love primarily concerns believers’ relationships with each other. Above all refers to the supreme importance of that virtue in the Christian life (cf. 1 Cor. 13:13; Phil. 2:2; Col. 3:14), and the participle rendered keep collects “sound judgment” and “sober spirit for the purpose of prayer” under the priority of fervent … love for one another. Fervent (ektenēs) denotes stretching or straining and pictures a person running with taut muscles, exerting maximum effort. Ancient Greek literature used the word to describe a horse stretching out and running at full speed. Earlier in this letter (1:22), Peter also used its related adverb to describe the intensity and exertion that ought to characterize Christian love. Such love is sacrificial, not sentimental, and requires a stretching of believers’ every spiritual muscle to love in spite of insult, injury, and misunderstanding from others (Prov. 10:12; Matt. 5:44; Mark 12:33; Rom. 12:14, 20; 1 John 4:11; cf. Rom. 12:15; Gal. 6:10; Eph. 5:2; James 1:27).
It is self-evident that genuine love inherently tends to forgive the offenses of others (cf. Prov. 10:12). But commentators differ on how to interpret the expression love covers a multitude of sins. Some say it refers to God’s love covering sins, whereas others say it describes believers who are lovingly overlooking each other’s transgressions. Since the text offers no explanation, it seems best to understand the phrase here as a general axiom. Whether from God or man, love covers sin.
Love derives from the well-known Greek word agapē (cf. 1:8, 22; 2:17; 3:10), which carries a strong volitional significance. Salvation results from the Lord’s choosing to love all those who believe: “But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us” (Rom. 5:8; cf. John 3:16; 1 John 4:19). Christians must follow His example, choosing to love even the unlovely, because “the whole Law and the Prophets” (Matt. 22:40) hinges on doing so (vv. 37–39), as does their witness (John 13:34–35). The command to be hospitable (literally, “to love strangers”) takes that love beyond the circle of Christians’ friends to other believers they do not even know (cf. Heb. 13:2).
According to the Mosaic law, the Jews were to extend hospitality to strangers (Ex. 22:21; Deut. 14:29; cf. Gen. 18:1–2). Jesus commended believers who provided food, clothing, and shelter to others (Matt. 25:35–40; cf. Luke 14:12–14). However, the spirit of hospitality extends beyond the tangible acts of providing meals or a place to stay. It includes not just the act, but an unselfish attitude, so that what is done, no matter the sacrifice, is done without complaint. Biblical hospitality knows nothing of the “Poor Richard’s Almanac” mentality that says fish and guests smell after three days.
Because believers still sin (Rom. 7:18–19; 1 John 1:8; cf. 1 Tim. 1:15), the only thing that will preserve the church’s unity is love that forgives and reaches out in kindness to strangers. Love also plays a foundational role in the evangelization of the unsaved. Jesus told the apostles, “By this all men will know that you are My disciples, if you have love for one another” (John 13:35).
8 In the mind of Peter, proper thinking will lead to proper action, and a distinctly Christian social ethic is the embodiment of love. Love for others, “above all,” is to characterize the Christian community, and such love is to be tenacious, full-bodied, intense, deep (ektenēs, GK 1756). If the NT teaches anything, it teaches the primacy of love in accord with the teaching of Jesus (Mk 12:31; Lk 10:27; Jn 13:34–35; 15:12; 1 Co 13:1–13; Eph 5:1–2; Php 2:2; Jas 2:8; 1 Jn 2:10; 4:7–11, 19–21). Moreover, in the face of extreme social hostility, love will be necessary for spiritual survival. For Peter the primacy of love is accompanied by a qualification, and this qualification is a partial citation of Proverbs 10:12 similar to James 5:20—“love covers over a multitude of sins,” rather than magnifying the faults of others. After all, love is patient and doesn’t keep a record of wrongs (1 Co 13:4, 5).
4:8 / Above all, as far as fellow believers are concerned, right relationships between them are paramount. The importance of the old tag “unity is strength” became increasingly obvious to the early Christians as members of their community faced hardening antagonism from neighbors and officials. The vital link between Christians is expressed by Peter’s admonition to his readers: above all, love each other deeply. And by way of supporting explanation, he once again turns to the ot for a proof-text: because love covers over a multitude of sins (Prov. 10:12). As a proverb, the expression perhaps originally meant “Love is blind to the faults of others.” It came to be interpreted by Jews as referring to deeds of love, especially almsgiving, that in the Jewish view helped to atone for an individual’s own sins. Significantly, in taking over the ot citation Peter changes the word for “love” to the usual nt term (agapē), and so points to the Christian understanding of the proverb. Love here refers to Christ’s love. At best, a Christian’s love is but a reflection of that of the Lord Jesus, and that is unique because it alone can “cover over sins.” Only Christ’s love is able to hide an individual’s sins from God’s consciousness (Rom. 5:9).
4:8. The second priority is forgiving love. Above all, love each other deeply burns into our minds the supreme importance of love as the controlling factor in all relationships in the church (see 1:22; 2:17; 3:8). This kind of love (agape) can be commanded because it is primarily a decision of the mind, not a feeling into which a person falls. The goal of agape love is always to seek the good of the other person. The evidence of agape love is action, not words. The extent of agape love is sacrifice. Thus, believers are to love each other “deeply.” This word means “to be stretched.” True agape love is constantly being stretched to the limit by the demands made on it. This is precisely where agape love shines, because it is not exhausted when it becomes difficult or inconvenient.
One of the most difficult and inconvenient times to extend love is when someone in the church has hurt or wronged us. We must demonstrate a love that is willing to be stretched because love covers over a multitude of sins. “Covers” means “willing to forgive.” The present tense indicates that which is to be constantly true in the life of the believer.
Love does not ignore the reality of personal sin any more than it justifies or condones sin. Confrontation of sin is appropriate and necessary, especially when we demonstrate love. However, it is just as important to demonstrate a willingness to forgive and then to move on. Forgiveness, like love, is an act of the will, a personal choice. A person chooses either to forgive or not to forgive. According to Grudem, “Where love abounds in a fellowship of Christians, many small offenses, and even some large ones, are overlooked and forgotten. But where love is lacking, every word is viewed with suspicion, every action is liable to misunderstanding, and conflicts abound” (Grudem, 174).
4:8 He must pay attention to his fellowship with other believers (vv. 8, 9), and have fervent love for all members of the household of faith. Such a love will not publicize the faults and failings of other believers, but will protect them from public view. Someone has said, “Hatred makes the worst of everything. Love is entitled to bury things out of sight.”
The statement “love will cover a multitude of sins” (Prov. 10:12) should not be taken as a doctrinal explanation of how sins are put away. The guilt and penalty of sins can only be removed by the blood of Christ. Neither should the statement be used to condone sin or to relieve an assembly from its responsibility to discipline an offender. It means that true love is able to overlook minor faults and failures in other believers.
4:8have fervent love among yourselves: Christian commitment for the good of one another is to be intense, stretched out to the maximum, holding nothing back. love will cover a multitude of sins: Peter is not suggesting that one Christian’s love atones for another Christian’s sins. Rather, by introducing this proverb from the OT (Prov. 10:12), he is reminding us that love does not stir up sins. We can demonstrate our love for our fellow believers by truly forgiving them and not talking openly about their past sins.
4:8–9. Love (agapēn … echontes) each other deeply. “Deeply” (ektenē, “stretched” or “strained”) was used to describe the taut muscles of an athlete who strains to win a race (cf. ektenōs in 1:22). A Christian’s unselfish love and concern for others should be exercised to the point of sacrificially giving for others’ welfare. Love covers over (kalyptei, lit., “hides”) a multitude of sins. This kind of strenuously maintained love is not blind but sees and accepts the faults of others (cf. Prov. 10:12; 1 Cor. 13:4–7). Christian love may be displayed through extending free food and lodging, offering hospitality (philoxenoi, lit., “being friendly to strangers”) without grumbling to those who are traveling. During times of persecution, hospitality was especially welcomed by Christians who were forced to journey to new areas.
 MacDonald, W. (1995). Believer’s Bible Commentary: Old and New Testaments. (A. Farstad, Ed.) (p. 2277). Nashville: Thomas Nelson.