Why is faith in Jesus important for eternal life?

Jesus makes it clear in John 3:15 that 'whosoever believeth in Him should not perish, but have eternal life.' This highlights the exclusivity of faith in Christ as the means to escape judgment and attain eternal life. Sinners who recognize their need and look to Him in faith are promised salvation. This reliance on faith emphasizes that it is not our works that save us, but belief in the completed work of Christ that guarantees eternal life. Salvation is entirely by grace through faith, a central tenet of sovereign grace theology.