How do we know Jesus' promise of life is true?

In John 14:19, Jesus reassures His disciples that because He lives, they too shall live. This statement not only reflects the reality of Jesus' resurrection but also serves as a key promise to all believers. The believer's life is fundamentally tied to Christ's life—through faith, they are united with Him. This union implies that the spiritual life received through faith in Christ is eternal and cannot be lost. The assurance of eternal life is a foundational aspect of Christian hope, rooted in Christ’s resurrection and His ongoing presence among believers.