How do we know Christ's atonement is effective?

The effectiveness of Christ's atonement rests on the belief that He was sinless and took upon Himself the sins of all God's elect. As Scripture teaches, He endured the anguish of God's wrath during His crucifixion, suffering in a way no human could ever comprehend. This is most clearly articulated during the three hours of darkness when He bore the penalty for our sins—a burden so great that only His divine nature could sustain such a payment. His sacrificial death was not just a general offering but an effective atonement that provides salvation to those whom the Father has given Him, ensuring that all for whom He died will be saved and justified by His blood.