How do we know Christ's death was a true atonement for sin?

The Bible clearly states in Matthew 20:28 that Christ came to give His life as a ransom for many, signifying that His death serves as an atonement for the sins of humanity. This foundational truth underscores that Christ's sacrificial death was not merely a moral example but a necessary act to satisfy God’s justice and reconcile sinners to Himself. Hebrews 9:14 and 1 Peter 3:18 further support this doctrine by affirming that Christ suffered for sin, the just for the unjust, to bring us to God. Understanding this atonement is crucial for grasping the full comfort and hope of the Gospel.