In the Bible God is revealed as a holy God, and all who enter into his presence must be clean. In the Old Testament, God gave Israel the tabernacle to sanctify the people so that he could dwell among them.
In Exodus 25, God said to Moses, “let them make me a sanctuary; that I may dwell among them” ~ (v.8). This was a type of the sanctuary and the true tabernacle which Jesus entered in the Heavens, when through his own blood, he entered into the presence of God for us, to make intercession for us.
Under the Law, the tabernacle and all that was in it, had to be first purified by the atoning blood before it could be put into service for the Living God to dwell among his people.
On the annual Day of Atonement, the tabernacle and everything that pertained to it, had to be purified again with the atoning blood because of the sins of the people. All that was associated with the presence of God had to be holy and purified by blood.
This was a foreshadowing of what Jesus would do to bring us near to God. The writer of Hebrews tells us the following:
Moreover he (Moses) sprinkled with blood both the tabernacle, and all the vessels of the ministry. And almost all things are by the law purged with blood; and without shedding of blood is no remission. It was therefore necessary that the patterns of things in the heavens should be purified with these; but the heavenly things themselves with better sacrifices than these. For Christ is not entered into the holy places made with hands, which are the figures of the true; but into heaven itself, now to appear in the presence of God for us… ~ Hebrews 9:21-24.
After he shed his blood on the cross as payment for our sins, Jesus entered into the very presence of God for us with his own blood to purify for us access to God so that we may live in his presence.
This is why the author of Hebrews tells us to enter with boldness into the holiest (the presence of God) by the blood of Jesus, by a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh; and having an high priest over the house of God; Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water. ~ Hebrews 10:19-22)