He has testified concerning His Son
1 John 5:9 New American Standard Bible
9 If we receive the testimony of people, the testimony of God is greater; for the testimony of God is this, that He has testified concerning His Son.
John here speaks of the testimony of God concerning His Son. During Jesus earthly ministry there were three events that truly testify to Jesus as the Son of God and in which the Father is directly involved. The first is Jesus baptism. When Jesus is baptized by John the Baptist and comes out of the water it is the Father who says, “this is my Son with whom I am well pleased”.
The Second is the mount of transfiguration. It is here upon this mountain that Jesus was transfigured before Peter, James, and John. It was on this mountain they saw Moses and Elijah. It is also here that they heard the Father say “this is my Son in whom I am well pleased.
The last is Jesus death and resurrection. It was upon the cross that Jesus cried “my God, my God why have you forsaken me”. It seemed that Jesus was cursed to die upon the tree. But three days later He rose from the grave to new life and His resurrection demonstrates that Jesus is exactly who He claimed to be.
In the previous verse John spoke the Spirit, the water, and the blood testify to Jesus as the Son of God. John is writing a letter to defend the deity of Jesus Christ. Under Jewish law the testimony of a single person was not valid. It required two to three witnesses. If all we had were the claims of Jesus it would not be valid. But the Father testifies Jesus is truly the Son of God through His virgin birth, through His baptism, through the mount of transfiguration, through his miracles, and most of all through His death and resurrection.
Our faith and practice are built upon the cornerstone of Jesus Christ. Satan will always attack the deity of who Jesus is. It is vital that our hearts and minds are daily immersed in the truth of God’s word and we spend time in God’s presence in prayer. Through abiding in Him on a daily basis we will not be shaken. No matter what Satan may assault our lives with, it will not stop what God is doing in us. When we examine the scriptures and the life of Jesus it is clear beyond a shadow of a doubt that Jesus is exactly who He claimed to be. He gave His life so that we could be reconciled to the Father, we would be redeemed, our debt would be paid, and we would be forgiven.