John 17:3, “And this is eternal life, that they know You, the only true God, and Jesus Christ whom You have sent.”
Eternal life is not as we usually think it. Eternal life for the Christian, we think, begins after death. That is not how Jesus describes it here. Rather, He says, eternal life is to know God. If you know God, you have eternal life, right here, right now. How do you know God? You can only know God if you know Jesus Christ, the Son of God. If you do not know the Son of God, you do not know God the Father. Use this as a comfort, O Christian. If you know Christ the Son of God, then you know you have eternal life for sure.
The Lutheran Column 