1 John 2:5 5but whoever keeps his word, truly the love of God is perfected in this one; in this we may know that we are in him.
This verse gives the opposite of verse 4 and expresses John’s intent for his readers. The conditional idea expresses the positive goal of keeping or obeying Jesus’ word. Word (logon) could refer to Jesus’ teachings, which for us would be recorded in the four Gospels, but it could also have the nuance of both the person of Jesus as the incarnated Word of God (John 1:1-4) and the message of the gospel he proclaimed. Obedience proves one’s faith and is the source of assurance that one is right with God.
As John writes later in verse 10, the specific focus of Jesus’ teaching is love. When one loves others as Jesus taught, God does a powerful, transformative work in that person. Obedience to Jesus has a specific goal: perfection in the love of God. Perfected (teteleiōtai) is in the perfect tense, indicating that God’s love has been growing in a person. God plants a seed of love in a person’s heart when that person first comes to believe. That seed grows into a beautiful plant over time, producing the fruit of love (Galatians 5:22). No one who truly believes is devoid of God’s love. The word perfected can mean coming to completion or reaching the intended goal or purpose. The genitive construction the love of God could refer to God’s love for us (subjective) or our love for God (objective). The two should not be separated.
However, God’s love for us is already perfect (Matthew 5:48), so it is love that needs to be perfected within us. The issue is our love for God and our experience of God’s love in our hearts. Our love for God and our experience of God’s love in our lives will grow as we obey Jesus. If we sense God’s love growing inwardly in our spirits, we will have the assurance that we are in good standing before God and have eternal life. If we lack love, sin likely has somehow infiltrated our lives and needs to be confessed and cleansed (1:9).