1 JOHN

That You May Know You Have Eternal Life

Ask the Apostle John

Ask about assurance of salvation, loving one another, or walking in the light.

A Cinematic Introduction

First John is not so much a letter as it is a pastoral sermon, written by the elderly apostle John to a group of churches under his care. A dangerous false teaching, an early form of Gnosticism, was threatening the community. These false teachers denied that Jesus had come in the flesh, claimed to possess a secret, superior knowledge of God, and lived lives of moral indifference. Their teaching was causing confusion and doubt among the believers. John writes with the heart of a loving spiritual father to counter this heresy and, most importantly, to give the true believers confidence and assurance of their salvation. The book is structured around a series of three repeating "tests" or evidences of genuine faith. John's logic is clear: if you are truly a child of God, your life will show evidence of it. He is not giving these tests to make people doubt, but so that believers "may know that you have eternal life" (1 John 5:13).

Test 1

The Doctrinal Test

Do you believe the right things about Jesus?

Confessing the Incarnate Christ

The Gnostic false teachers taught that spirit is good and matter is evil. Therefore, they could not accept that the divine Son of God would take on a true human body. They denied the Incarnation. John makes this belief the primary test of a true spirit versus a false one.

✨ “This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist.”

— 1 John 4:2-3

For John, correct theology about the person of Jesus is non-negotiable. Genuine faith is not a vague spirituality, but a firm belief in the historical, biblical Jesus—fully God and fully man. To deny the humanity of Jesus is to deny the reality of His sacrifice on the cross.

Test 2

The Moral Test

Do you live a life of obedience?

Walking in the Light

The false teachers claimed to "know God" and have "fellowship with him" while continuing to live in sin. John exposes this as a lie. He uses the stark contrast of light and darkness. God is light; in Him there is no darkness at all. Therefore, to claim to have fellowship with Him while walking in darkness is a contradiction.

"We know that we have come to know him if we keep his commands. Whoever says, 'I know him,' but does not do what he commands is a liar, and the truth is not in that person." - 1 John 2:3-4

John is not teaching a sinless perfectionism. He is clear that if we claim to be without sin, we deceive ourselves (1:8). But he is teaching that the overall direction and desire of a true believer's life will be toward obedience. A person who is genuinely "born of God" cannot make a continual, comfortable practice of sin, because God's "seed" remains in them (3:9).

Test 3

The Social Test

Do you love other believers?

The Ultimate Evidence

For John, the most conclusive and visible evidence of a person's salvation is their love for other Christians. This is the test he returns to again and again, with increasing intensity. The Gnostic teachers were arrogant and elitist, separating themselves from the community. John declares that this lack of love proves their claim to know God is false.

✨ “We know that we have passed from death to life, because we love each other. Anyone who does not love remains in death.”

— 1 John 3:14

This love is not just a warm feeling; it is a practical, self-sacrificing action, modeled on Christ himself: "This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters" (3:16). If we see a brother or sister in need and have the material resources to help them but do nothing, John asks, "how can the love of God be in that person?" (3:17).

Conclusion: The Confidence of True Faith

First John is a profound gift to the Church. It provides believers with a diagnostic tool to examine their faith and find assurance. It is not meant to create doubt, but to replace a false, insecure hope with a solid, confident one. John's message is simple: A true Christian believes the truth about Jesus, desires to live an obedient life, and demonstrates a practical love for other believers. Where these three marks are present—even imperfectly—a person can have confidence that they have been born of God and possess eternal life. It is a loving, pastoral call to a faith that is real, visible, and sure.