Matthew 11:27
"All things have been entrusted to me by my Father and no one [truly] knows the Son except the Father. And neither does anyone [truly] know the Father except the Son and that person to whom the Son wants to reveal Him.
John 17:3
And this is never ending life; that people may know you [as] the only true God, and Jesus Christ, the One whom you have sent.
1 John 5:20
And [in addition], we know that the Son of God has come [in a physical body, See 4:2] and has given us understanding, so that we can know the True One [i.e., God], and that we are in [fellowship with] the True One, even His Son Jesus Christ. This Son is the true God and eternal life.