Anyone can say the phrase “Jesus is the Son of God” but merely saying these words is nothing compared to confessing that Jesus is the Son of God!
Only the Holy Spirit can reveal 1) a person’s sinfulness to them, 2) the identity of Jesus as the Son of God, 3) their need to repent and 4) receive Jesus as their Saviour and Lord, to cleanse them of their sins and make them a child of God.
In such a person, the Holy Spirit will dwell and continue His work of sanctification, of the renewing of their mind, granting them a desire to walk with Jesus, be more like Him and do the good works He has called them to do.
Dear Christian, have you confessed with your mouth that Jesus is Lord and believed that God has raised Him from the dead?