Why do Christians believe in eternal life?

The belief in eternal life is a central tenet of Christianity supported by various Scriptures. Jesus affirms in John 3:15 that 'whoever believes in him shall not perish but have eternal life.' This promise is echoed throughout the New Testament, reinforcing that through faith in Christ's resurrection, believers are granted eternal life. The nature of eternal life encompasses a relationship with God, as stated in John 17:3, where eternal life is knowing the only true God and Jesus Christ. Moreover, the teachings of the apostles, including the assurance of being raised with Christ in glory (Colossians 3:4), solidify the hope of eternal life for those who are in Him.