In 1 John 4:13-17, John explains the work of the Holy Spirit in producing love in believers and giving them assurance of their salvation.
The Spirit produces the good work in us (verse 13)
Every believer receives the Holy Spirit at conversion (Ephesians 1:13). His work is to take the completed work of the Son and applies it in the believer’s life (Romans 8:11).
The Spirit convinces believers of truth (verse 14; 1 John 2:27)
The Spirit interprets and affirms scripture (which cannot be understood apart from him) (1 Corinthians 2:13-14). He does not impart truth apart from the external presentation of God’s word (Romans 10:14). This applies to both our initial recognition of truth as well as subsequent learning.
The Spirit compels us to obedience (verse 15)
Confesses is different from believes in that confessing includes agreement and implies commitment. To confess Jesus is agreement and commitment to his lordship. This confession of lordship is part of conversion (Romans 10:9). Ongoing commitment to lordship is part of following Jesus (Mark 8:34). Faithfulness to Jesus’ lordship is only possible with the Spirit (1 Corinthians 12:3b), who regenerates and renews us (Titus 3:5), frees us from bondage to sin (Romans 8:2), and enables obedience (Ezekiel 35:27).
All that John has just described makes up the love that God has for us (verse 16)
God lives in us (verse 13). He has revealed himself to us (verse 14) and transforms us into something infinitely better than what we were (verse 15). It is in experiencing these things that we know and experience the love that God has for us.
The Spirit produces and perfects love in believers (verse 17a; Galatians 5:22-24)
The fruit of the Spirit is singular (not, the fruits of the Spirit are), and love is the preeminent element of this fruit.
Love is the key. Joy is love singing. Peace is love resting. Long-suffering is love enduring. Kindness is love’s touch. Goodness is love’s character. Faithfulness is love’s habit. Gentleness is love’s self-forgetfulness. Self-control is love holding the reins. —Donald Grey Barnhouse
Love does not just spontaneously appear. God cultivates the soil of a believer’s heart and prunes branches to produce more fruit (John 15:2).
The Spirit’s presence provides assurance of salvation (verse 17b; Ephesians 1:13-14)
You know the Spirit is present because he convinces you of truth, because he compels you to obedience, and because he produces love in you where there was no love before.