A study on Christian maturity, the two natures, and the purpose of John’s exhortation.
John writes to people he already identifies as born again. Throughout the letter he calls them “little children,” “beloved,” and “born of God.” His purpose is not to make them question their salvation but to help them walk in fellowship with God.
The phrase “let us…” shows that 1 John 3:18 is an exhortation. John is urging believers to let the love of their new nature express itself in real, tangible actions. This is the language of practice, not proof of salvation.
John is not saying, “If you don’t love perfectly, you were never saved.” He is saying, “Because you are God’s children, let your love be real.”
John’s teaching becomes clear when we recognize that believers have two natures:
When believers love, the new nature is expressing itself. When they fail to love, the old nature is expressing itself. Neither expression changes the fact of the new birth.
Agapē (ἀγάπη) John uses agapē to describe the kind of love that originates in God’s own nature. This is not sentiment or emotion-driven kindness. It is self-giving, others-oriented love that seeks the good of another at personal cost. In 1 John, agapē is always tied to God’s character (“God is love”) and to the believer’s new nature (“everyone who loves has been born of God”).
Alētheia (ἀλήθεια) The word alētheia means “truth,” but in John’s writings it carries the sense of reality, genuineness, and alignment with God’s character. To love “in truth” means to love in a way consistent with God’s nature, God’s Word, and the believer’s new identity. It is love that is not performative or merely verbal.
Together in 1 John 3:18 John’s pairing of “deed” and “truth” shows that Christian love is both active and authentic. It is not measured by intensity of feeling but by the presence of real, concrete actions that reflect God’s character. This reinforces that the verse is about maturity, NOT qualification for salvation.
Many Christians read 1 John as a list of “tests” to determine whether they are truly saved. But John’s stated purpose is assurance and fellowship, not doubt. His “you know” statements are meant as reassurances, not threats.
When John says, “We know we have passed from death to life because we love the brothers” (3:14), he is not giving a checklist. He is pointing out that love is evidence of the new nature at work — something believers can take comfort in.
Scripture speaks of salvation in three tenses:
1 John 3:18 belongs entirely to the present (2nd) tense of salvation — sanctification. It describes how God’s children grow, mature, and express the life they already possess. It does not address the past (1st) tense of salvation — the moment of new birth — nor the future (3rd) tense — glorification.
1 John 3:18 is not a test to determine whether someone is truly born again. It is a call to believers — God’s already-born children — to let the love of their new nature show up in real, practical ways. John’s concern is fellowship, maturity, and spiritual growth, not questioning the reality of the new birth.