Why is the concept of a sinless Savior important for Christians?

The sinlessness of Christ is crucial for Christians because it underscores His role as our perfect Substitute. If Christ had sin, He could not take our place in bearing the penalty for sin. Hebrews 4:15 speaks to this point, stating that we do not have a High Priest who is unable to empathize with our weaknesses, but rather one who has been tempted in every way, yet He did not sin. This allows believers to have confidence in our standing before God, knowing that our Mediator is holy and without sin, providing assurance of our acceptance by the Father.