1 John 5:1 Whosoever believeth that Jesus is the Christ is born of God: . . . (a born again Christian).
Believing in Jesus is more than head knowledge, it's acknowledging Christ and His shed blood as your only hope of forgiveness and salvation. It's asking Him into your heart and life, to be your personal Savior.
The Holy Spirit moves into your heart the instant you believe in Jesus.
Romans 10:13 For whosoever shall call upon the name of the Lord shall be saved. (saved from Hell).
The Spirit of God speaks to your heart, guides you, warns you, leads you, and comforts you.
Romans 8:9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwells in you. Now if any man have not the Spirit of Christ, he is none of his.
The Spirit of God gives you a desire to hear and understand and act on the Word of God.