Note 4 at Joh 1:16: It is evident from the context that John was speaking to believers and saying that all believers have received the fullness of Jesus. Those who reject the salvation that Jesus offers have not received the fullness of Jesus.

This is an awesome statement. Jesus had the fullness of the Godhead in Him (Col 2:9), and to those of us who receive Jesus into our lives, we also have the fullness of God in us. We are complete in Jesus (Col 2:10). The rest of the Christian life is not trying to obtain more from God but rather renewing our minds to what we have already received through Christ (see note 3 at Mt 26:41).