1 John 4:15

If anyone acknowledges that Jesus is the Son of God, God lives in them and they in God. – NIV

Simply put, whoever acknowledges that Jesus is the Son of God now has God living in him, and that person lives in God. 

This requires that a person trust that Jesus is God’s Son, this is essential to knowing God. Jesus is both human and God. It may be difficult to understand it, but we must accept Jesus as both human and God. If he wasn’t  human, He could not die and rise again. If he wasn’t God, he could not be without sin and offer Himself as a perfect sacrifice. Acceptance and acknowledgement of both aspects of His being are vital to our salvation.