How do we know that Christians have eternal life?

Christians possess the promise of eternal life because the resurrection of Jesus serves as a guarantee of their own future resurrection and eternal communion with God. In 1 Corinthians 15, Paul asserts that because Christ has risen, believers will also experience a transformation from corruptible to incorruptible bodies. The assurance of eternal life is rooted in the victory over death that Christ achieved on their behalf. As believers are united with Christ in His death, they will also be united with Him in His resurrection, affirming that they will dwell with Him for all eternity, free from sin and death’s hold.