Why is Christ's finished work essential for forgiveness?

The finished work of Christ is central to the Christian faith because it is through His sacrifice that believers receive forgiveness for their sins. Hebrews 10:14 states that by a single offering, Christ has perfected for all time those who are being sanctified. This means that His atonement is sufficient to cover all sins—past, present, and future—and assures believers of their righteousness in God's eyes. Through faith in His completed work, we recognize that no additional effort or works are necessary for salvation, emphasizing the grace offered through Christ alone.