How do we know the doctrine of eternal life is true?

The assurance of eternal life is grounded in the teachings of Scripture, particularly in passages like 1 John 5:12 which states, 'He who has the Son has life; he who does not have the Son of God does not have life.' Eternal life is presented as both a present reality and a future hope for those who have faith in Christ. It is crucial to understand that this eternal life is not merely a duration of existence but is centered on knowing God, as seen in John 17:3, which states, 'And this is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent.' Thus, belief in the person and work of Jesus is foundational to grasping the truth of eternal life.