John's twin goal: prevention and provision. He writes for our sinlessness, but he is realistic about our sin.

Advocate — Greek paraklētos, the same word used of the Holy Spirit in John 14:16. The Spirit is our Advocate within; Christ is our Advocate above.

Propitiation — Greek hilasmos, that which turns away wrath. Christ Himself is both the priest and the sacrifice; the offering and the One who presents it.

The whole world — His sacrifice is sufficient for all, while applied to those who believe. The verse argues against any narrow restriction of Christ's atoning value.

First test: obedience. Not perfectly, but characteristically. The Christian does not lose interest in obeying; that interest itself is evidence of new life.

John's know (Greek ginōskō) is experiential. To know that we know Him is the inward witness of fellowship.

The Christian life is not measured by the standard of the average believer but by the standard of Christ Himself. As he walked — that is the ruler.

A practical hermeneutic: when in doubt about a course of action, ask what He would have done.

Second test: love of the brethren. Hatred of a fellow believer disproves any profession of being in the light, no matter how loud or sincere.

A diagnostic verse for the social-media era. Posture without love is darkness in costume.

World here is not creation, not people, but the organized system of human society in rebellion against God. The same writer says God loved the world (John 3:16), where the meaning is the people.

Two loves cannot occupy the same chair. Whatever ascends in our affections at the expense of the Father will displace Him.

A famous three-fold classification of temptation. The same trio appears in Eden (Gen 3:6 — good for food, pleasant to the eyes, to make one wise) and in Christ's wilderness test (Matt 4 — stones to bread, glittering kingdoms, leap from the pinnacle).

Every form of temptation we face can be sorted into one of these three.

The reason not to love the world: it is dissolving even as we cling to it. Investing the heart in what is being subtracted from the universe is bad theology and worse economics.

Doeth the will of God — note John's emphasis on doing, not merely believing. The same accent runs through James.

Antichrist — both a person yet to come and a spirit already at work. The two are not mutually exclusive; the spirit foreshadows the person.

The last time — the whole age from Christ's ascension to His return is the New Testament's last days (Hebrews 1:2).

John defines antichrist doctrinally before he defines it politically. To deny that Jesus is the Christ — or to deny His true relation to the Father — is the substance of antichrist teaching.

A useful diagnostic for false teaching in any era: what does it say of Christ, and of His sonship to the Father?

The Spirit is the anointing — the same Greek word as the title Christ (Anointed One). Believers share by grace what He bears by nature.

Need not that any man teach you — does not abolish human teachers (John himself is teaching). It means the believer is not at the mercy of any single teacher; the Spirit's witness within authenticates true doctrine.

A pastoral aim: that no believer be embarrassed at His appearing. The way to that confidence is abiding — staying connected, not falling away.

Confidence — Greek parrēsia, openness of speech, the boldness of a child before a loving Father.