How do we know that redemption through Christ is true?

The Christian doctrine of redemption through Christ is rooted in the fulfillment of prophecy and the testimony of Scripture. Jesus proclaimed 'It is finished' (John 19:30) at His crucifixion, signaling the completion of the redemptive work He came to accomplish. This is supported by the New Testament writers, who emphasize that His blood is the 'blood of the everlasting covenant' (Hebrews 13:20) and that it cleanses from all sin (1 John 1:7). Moreover, the evidence of Christ's resurrection is a pivotal affirmation of His victory over sin and death, as noted in Romans 4:25. With God, all promises are sure, and nothing can thwart His plans, ensuring that redemption in Christ is not only attainable but guaranteed for all who believe.