1 John 4:14-15, “And we have seen and testify that the Father has sent his Son to be the Savior of the world. Whoever confesses that Jesus is the Son of God, God abides in him and he in God.”
John is here saying the same thing in two complimentary ways. To confess Jesus as the Son of God IS to see and testify that the Father sent the Son as the Savior of the world, and vis versa. In other words, confession of Jesus as the Son of God is not merely—or mainly—confession of an ontological status, rather, it is confession of an act-revealed identity. To confess Jesus as Son of God is to confess Jesus as the one sent by the Father as savior of the world. The sent-ness of the Son—and so the salvific (i.e., revelatory) death of the Son, and so the LOVE of God who is LOVE—is inseparable from and inherent to the confession of Jesus as the Son.
Yes, to confess Jesus as the Son of God IS to confess the love of God since it is to confess Jesus as the one sent from the Father as Savior of the world / as the one who gives us life (=reveals God) / as wrath-absorbing sacrifice / as the Love of God (v.10).
What John says next confirms that true confession of Jesus as SON is confession of God’s LOVE —>
1 John 4:16, “So we have come to know and to believe the love that God has for us.”
The Father’s sending of the Son is His love, and so to see and testify to the sent-ness of the Son (a.k.a., to confess Jesus as the Son who has been sent) IS to know and believe the love God has for us.
Finally, bear in mind that all of this is possible only by the indwelling Spirit (v.13). It is the Spirit alone who causes us to recognize the sending of the Son as love for us, as the personal love of God, as a love that can be known and believed and abided in. The confession of Christ as the Son of God, the Sent One, the Savior, the Propitiator, the Life-Giver, these are all true and good and necessary confessions, but we miss the point if we do not recognize that to confess these things is to confess the love which God has for us….And to confess the love which God has for us is to confess who God is toward us…it is to confess Jesus Christ, the crucified and risen Son of God.