“He who believes in the Son of God has the witness in himself; he who does not believe God has made Him a liar, because he has not believed the testimony that God has given of His Son.”
In this verse, we come to the experiential witness to the Son of God – the indwelling Holy Spirit in every true believer.
He who believes in
The phrase “he who believes in the Son of God” picks up the idea of belief in verse one. John uses the grammatical construction “believe in” thirty-seven times. This is the first occurrence of the word “believe” combined with “in” in 1 John. The idea is that faith rests in an object. Faith fully relies upon the person of the Son of God.
the Son of God
The Son of God is the great object of 1 John.
has the witness in himself;
The indwelling Holy Spirit is the internal witness to the heart of the true believer. Every truly born again believer has the indwelling Holy Spirit in him. The internal witness of the Spirit gives the Christian assurance that he was right in believing in Jesus as the Son of God.
Faith brings the believer a consciousness of the dynamic indwelling of the Holy Spirit. The Holy Spirit inwardly witnesses to the truth of salvation. Christians receive a conscious assurance of their salvation due to Him.
We can not only be sure what we believe but that we believe.
Assurance does not rest on our emotions but an inner witness from the Holy Spirit. Trust in the Son of God makes possible the inner witness of the Holy Spirit to our salvation.
Ro 8:16-17, 16 “The Spirit Himself bears witness with our spirit that we are children of God, 17 and if children, then heirs—heirs of God and joint heirs with Christ, if indeed we suffer with Him, that we may also be glorified together.”
Ga 4:6-7, 6 “And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, ‘Abba, Father!’ 7 Therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ.”
Some Christians do not know that they have the indwelling Holy Spirit in them. They know that they believe in Jesus, but they do not know about the residing Holy Spirit. Each person who believes in Jesus has the Holy Spirit in him. The Holy Spirit takes up residence in each Christian at the point of salvation and stays there until he goes to be with the Lord (Ep 4:30).
The Christian is a shrine or sacred place because of the indwelling Holy Spirit. How we feel about this is irrelevant. It does not make any difference whether or not you know, understand, or believe it. The issue is whether the Holy Spirit confirms our faith in the Son of God. Faith takes God at His Word.
When a believer comes to the place where he knows that he has received the Holy Spirit, as well as the Lord Jesus, it is then that he permits the Holy Spirit to do something in him and for him. He recognizes the Holy Spirit’s presence. He ignored the Holy Spirit before, but now he knows he is a Christian.