Why is the concept of 'no work' important in salvation?

The instruction in Leviticus 16 that no work was to be done on the Day of Atonement serves as a powerful reminder that atonement for sin is a divine initiative, not achieved through human effort. This principle underscores the Reformed view of justification by faith alone, where salvation is fully dependent on Christ's completed work. Thus, it points believers to rest in Christ's sufficiency, affirming that their justification is not a result of their works but through faith in the grace of God, reinforcing the core tenets of the Five Solas.