Today is Yom Kippur, one of the high and holy days of the Jewish calendar. We know it from the Old Testament as the Day of Atonement, the one day once a year that the high priest would enter the Holy of Holies in the Temple in Jerusalem. The high priest would enter the inner sanctum in order to sprinkle the blood of the lamb on the mercy seat of the ark of the covenant for the sins of the people each year.
The writer to the book of Hebrew goes into great detail about this when speaking of Christ's sacrifice on our behalf...
"The first covenant had regulations for worship and an earthly sanctuary. A tabernacle was set up, and in its first room were the lampstand, the table and the consecrated bread; this was called the Holy Place. Behind the second curtain was a room called the Most Holy Place, which had the golden altar of incense and the gold-covered ark of the covenant. This ark contained the gold jar of manna, Aaron’s staff that had budded, and the stone tablets of the covenant. Above the ark were the cherubim of the Glory, overshadowing the atonement cover. When everything had been arranged like this, the priests entered regularly into the outer room to carry on their ministry. But only the high priest entered the inner room, and that only once a year, and never without blood, which he offered for himself and for the sins the people had committed in ignorance. The Holy Spirit was showing by this that the way into the Most Holy Place had not yet been disclosed as long as the first tabernacle was still standing. This is an illustration for the present time, indicating that the gifts and sacrifices being offered were not able to clear the conscience of the worshiper. They were only a matter of food and drink and various ceremonial washings—external regulations applied until the time of the new order. For this reason Christ is the mediator of a new covenant, that those who are called may receive the promised eternal inheritance—now that he has died as a ransom to set them free from the sins committed under the first covenant. When Christ came as high priest of the good things that are already here, he went through the greater and more perfect tabernacle that is not man-made, that is to say, not a part of this creation. He did not enter by means of the blood of goats and calves; but he entered the Most Holy Place once and for all by his own blood, having obtained eternal redemption." (Hebrews 9)
Happy Yom Kippur - Blessed Day of Atonement! Thanks be to God for redemption and salvation through the blood of Christ!