Why is Jesus's sacrifice important for Christians?

The significance of Jesus’s sacrifice lies in its completeness and efficacy. Hebrews 7:27 states that He 'offered up Himself' as a sacrifice once for all, eliminating the need for continual sacrifices like those of the Levitical priests. His substitutionary atonement means that all of our sins, past, present, and future, are fully paid for. This allows believers to stand justified before God without any accusations against them. It emphasizes that salvation is not contingent upon our works but is fully accomplished by Christ, pointing to the doctrine of grace and the assurance of salvation for the elect.