Please read the passage before reading the commentary.
“Who is the victor over the world? He one who believes that Jesus is the Son of God.”
Jesus Christ came through water and Blood, through the waters of baptism at the River Jordan and through the blood shed on the cross in his dying for us (this is the span of Jesus’ public life). On the testimony of two or three witnesses, we have the truth of Jesus Christ. Water and blood are two witnesses, and the Holy Spiri is the third.
At the baptism of Jesus the heavens were opened, the Spirit came upon Jesus, and the Father’s voice proclaimed Jesus as the Father’s Son. After the crucifixion, the Father raised Jesus from the dead and seated him at the Father’s right hand in heaven. In this glorifying of Jesus, the Holy Spirit is poured out over the whole world enabling us to acclaim Jesus as Lord, to the glory of the Father. The Spirit, the water and the blood attest to Jesus Christ as the Son of God.
All who believe in Jesus as the Son of God have this testimony of God within themselves. They also have God’s life in them. They are also Christians, not anti-Christs, because they have both the Son and the Father.
John comes to the end of his letter. Why did he write it? He wanted us to know that we have eternal life by believing in the Son of God. This believing is more than just something we say, it is something that we are. It is our relationship with the Son and Father. Just as the Father and the Son have this intimate relationship with each other, so likewise, since we know the Father and the Son, we have to maintain an intimate relationship with the Father and the Son.