A Biblical Theology of 1 John
The First Letter of John, one of the 3 Johannine letters, is one of the most challenging New Testament writings to interpret. Although brief—just five chapters—it is filled with profound theological themes, urgent exhortations, and strikingly absolute language. Unlike a typical letter, 1 John lacks sender, recipient, and greeting. Instead, it functions more like a tract, written to address division within the Johannine community and to reassure faithful believers that they belong to God through Jesus Christ.
The biblical theology of 1 John centers on the proclamation that “God is light” (1 John 1:5) and that “God is love” (1 John 4:8). Around these declarations, the letter weaves themes of truth, sin, love, knowledge, the Spirit, and the atoning death of Jesus. By doing so, it both confronts false teachers and strengthens the community’s confidence in the Gospel.
1. The Setting and Purpose of 1 John
1 John was written in the context of division. Some within the Johannine churches had left the community, rejecting key elements of the apostolic tradition. The author describes them as those who “went out from us, but they were not of us” (1 John 2:19). These opponents seem to have downplayed the importance of Jesus, emphasizing the Spirit to the exclusion of the Son. Some denied that Jesus came in the flesh (1 John 4:2), others claimed sinlessness (1 John 1:8), and still others disregarded the command to love.
The purpose of the letter is both polemical and pastoral. It refutes false claims while exhorting the faithful to remain in “what was from the beginning” (1 John 1:1; 2:24). The letter insists that true Christian life is grounded in the historical Jesus, continues in obedience and love, and is sustained by the Spirit of truth.
2. Structure and Style of the Letter
Though lacking the form of a letter, 1 John has a clear shape. After the prologue (1 John 1:1–4), two main sections unfold:
The first half, introduced by the statement “God is light” (1 John 1:5), emphasizes walking in truth and holiness.
The second half, introduced by “this is the message you have heard… that we should love one another” (1 John 3:11), highlights love as the defining mark of God’s children.
The epilogue (1 John 5:13–21) assures readers of eternal life and warns against idolatry. Throughout, the author uses “catchword” transitions, linking sections by repeating key terms like “abide,” “truth,” and “love.”
This structure mirrors the Gospel of John, with its prologue, two major sections, and epilogue, showing that both writings share a unified theological vision centered on Jesus Christ.
3. Christology and the Atoning Death of Jesus
At the heart of 1 John is the confession that Jesus is the Christ, the Son of God. To “do away with Jesus,” as the opponents effectively did, is to reject God himself (1 John 2:22–23). By contrast, to confess the Son is to have the Father (1 John 4:15).
The letter emphasizes the atoning death of Jesus more strongly than the Gospel of John. “The blood of Jesus his Son cleanses us from all sin” (1 John 1:7). He is “the propitiation for our sins, and not for ours only but also for the sins of the whole world” (1 John 2:2; 4:10). Jesus appeared “to take away sins” (1 John 3:5) and “to destroy the works of the devil” (1 John 3:8).
This focus ties directly to the Gospel as Anthony Delgado frames it: salvation is not merely forgiveness but liberation into Christ’s kingship. The death of Christ secures forgiveness, but it also defines the new way of life for God’s people.
4. Sin, Forgiveness, and the Call to Holiness
A key controversy in the community concerned sin. Some claimed they had no sin (1 John 1:8–10), perhaps believing the Spirit had rendered them perfect. The author rejects this. Believers are freed from sin’s dominion but still need cleansing. If they sin, “we have an advocate with the Father, Jesus Christ the righteous” (1 John 2:1).
At the same time, the letter insists that those born of God do not continue in sin (1 John 3:9). This tension reflects the “already and not yet” character of salvation: Christians are forgiven and transformed, but they still await final perfection when Christ appears (1 John 3:2).
The biblical theology of 1 John thus presents sin seriously, forgiveness generously, and holiness as essential. Grace is never an excuse for lawlessness; it empowers obedience.
5. Love of God and Love of One Another
The central ethical command of 1 John is love. Believers must love “one another” (1 John 3:11, 23; 4:7, 21). This love is modeled on God’s love in sending his Son: “By this we know love, that he laid down his life for us” (1 John 3:16). Love is practical, expressed in deeds, not words only (1 John 3:18).
Love for others cannot be separated from love for God. “He who does not love his brother whom he has seen cannot love God whom he has not seen” (1 John 4:20). In this way, love is both a test of true knowledge of God and a foretaste of eschatological confidence: “Perfect love casts out fear” on the day of judgment (1 John 4:18).
Here, love functions covenantally. To belong to God’s people is to be shaped by God’s love. Love also functions eschatologically, for it reveals participation in the life of the coming kingdom.
6. Knowledge of God and the Test of Truth
One of the repeated claims in 1 John is that believers “know God.” The opponents claimed this knowledge while denying Christ and disregarding love. The author therefore provides tests:
The doctrinal test: confessing Jesus as the Christ who came in the flesh (1 John 4:2).
The moral test: keeping God’s commandments (1 John 2:3–6).
The social test: loving one another (1 John 2:10; 3:14).
These three tests—truth, obedience, and love—interlock. Genuine knowledge of God is always marked by all three. This holistic vision resists both intellectualism without love and sentimentality without truth.
7. The Spirit of Truth and the Spirit of Deception
Another key theme is discernment of spirits. The author exhorts believers: “Do not believe every spirit, but test the spirits to see whether they are from God” (1 John 4:1). Those who confess that Jesus came in the flesh have the Spirit of God; those who deny him manifest the spirit of antichrist (1 John 4:2–3).
This distinction reflects the apocalyptic worldview of the letter. Humanity is divided into two realms: those “of God” and those “of the world.” Yet the assurance given is striking: “He who is in you is greater than he who is in the world” (1 John 4:4).
For the church today, this theology emphasizes the need for discernment. The Spirit of truth anchors believers in the Gospel; the spirit of deception always seeks to minimize or distort Christ.
8. Eschatology and the Hope of Christ’s Appearing
1 John situates Christian life within the “last hour” (1 John 2:18). The presence of “many antichrists” signals the nearness of the end. Yet the ultimate hope is Christ’s appearing: “When he appears we shall be like him, because we shall see him as he is” (1 John 3:2).
This eschatological vision gives confidence. Believers who abide in Christ will not shrink back at his coming (1 John 2:28). Love casts out fear (1 John 4:17–18). Eternal life is already present but will be fully revealed in the future (1 John 5:13).
In this way, 1 John integrates present assurance with future hope. The Gospel is both already fulfilled in Christ’s death and resurrection, and still awaiting consummation in his return.
Conclusion
A biblical theology of 1 John shows how deeply the Gospel shapes belief, obedience, and love. Written to a divided community, the letter reassures the faithful that they have eternal life in Christ while calling them to holiness, love, and discernment. It emphasizes the atoning death of Jesus, the necessity of abiding in what was from the beginning, and the Spirit’s role in guiding God’s people.
The letter’s uncompromising dualism can feel stark, but its aim is pastoral: to comfort the faithful and warn against deception. For the church today, 1 John remains a guide for Gospel-centered assurance, reminding us that to know God is to confess Christ, obey his commands, and love one another while awaiting the day when Christ appears in glory.
