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In the Old Testament, the people of God would mark holy days with remembrance and feasts. One of these days would be rightly described as the “most holy” of such days – for it was when the high priest would enter the Holy of Holies and stand before God to make payment for the sins of the people. This once-a-year sacrifice would be a foreshadowing of the long-foretold sacrifice of the Messiah. But long before He came, the people of God observed this day known as the Day of Atonement.