Why is faith in Christ essential for eternal life?

Faith in Christ is crucial for eternal life as highlighted in John 3:18, 'He that believeth on him is not condemned, but he that believeth not is condemned already...' This suggests that through faith, an individual connects with the life-giving power of Christ. It is not merely a matter of intellectual assent but involves trusting in His sacrifice and what He accomplished on the cross. The assurance of eternal life stems from this relationship; therefore, faith serves as the means by which believers receive the grace of God, which grants them eternal life, rescuing them from condemnation.