While some argue that the verb tenses of “believes” (ho pisteuōn)
and “is born” (gegennētai) in 5:1a indicate that being born of God
(i.e., regeneration) logically precedes faith, others argue
against taking the verbs in this way. Both positions miss John’s point,
however, which is evidential. Belief that Jesus is the Christ is
evidence of rebirth, and that is the important point for John since proper
belief in Jesus is what demarcates those who belong to God and those who do
not. John’s concern is not to establish a theological ordo salutis that
posits regeneration prior to faith. That does not mean that this verse opposes
that theological position, but it is not what John has in view.
Furthermore, “everyone who loves the father loves his child as well”
(5:1b). While “his child” could refer to Jesus (since it is literally “the one
born of him,” ton gegennēmenon; cf. 5:18), the next verse clarifies that
John means other believers. Love for God is raised in 2:5, 15; 3:17(?); 4:10
(negatively), and 4:20–21. Love for others is seen in 2:9–11; 3:10–12, 16–18;
4:7, 11–12, 21. The correlation between love for God and love for others is
seen in 3:16; 4:11, and 4:20–21. As indicated in that last reference, loving
God must result in love for brothers and sisters. “Loving one another is
a sign of how much we love God.”
While love for others is evidence of love for God, here John flips it
the other way also: “This is how we know that we love the children of God: by
loving God and carrying out his commands” (5:2). The kind of love for others
that is required of believers is determined by love for God. Loving God and
living his way is the sure sign that believers will rightly love others. This
is because God is love, and our love comes from him, but it is also what we
need from each other. We need to be encouraged by others’ love for God. Our
love for him helps others to love him better. And so love for God is a key
component in loving others. (Constantine R. Campbell, 1, 2, & 3 John [The
Story of God Bible Commentary; Grand Rapids, Mich.: Zondervan, 2017], 154-55)
