We forget that knowing God is already eternal life. John 17:3 says, "Now this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent." Who is talking here? Not St. John the Evangelist. This is Jesus speaking to the Apostles before His Passion. Why do we seek to follow Jesus? Because in doing so, we obtain peace and direction in life. But we also follow him because we are seeking eternal life. When we convert to follow Christ, our eternal life is already begun. That's what Jesus said!