How do we know that Christ is our total substitute?

The doctrine of Christ as our total substitute is grounded in the understanding that He both offered the sacrifice and was the sacrifice itself. In the Old Testament, animal sacrifices were just types pointing to Christ's perfect offering. Hebrews 9:14 confirms that Christ offered Himself without spot to God, thus fulfilling the law's requirements for sin atonement. This act secures believers' redemption and allows them access to God, showcasing His role as our mediator and total substitute.