Heb. 9:24 ... "Christ did not enter a holy place made with hands, a mere copy of the true one, but into heaven itself, now to appear in the presence of God for us."
A priest is one who has been appointed to officiate in holy things unto God on behalf of others. This sacred service is usually performed in a special place, called a "sanctuary," because the Deity has set it aside for that purpose. In the Mosaic system there was an order of priests, restricted to the tribe of Levi, who were appointed by God to officiate in holy things unto Him on behalf of all the other people of Israel, (Heb. 5:1-4). "There are those who offer the gifts according to the Law, who serve a copy and shadow of the heavenly things," (Heb. 8:4b-5a). These were the Levitical priests who performed their duties within the Tabernacle, (and later in the Temple), which was divided by an ornate curtain into two rooms. The first of them was exactly twice the size of the other. The larger was called the "Holy Place," and the smaller the "Holy of Holies," that is, the "Most Holy Place." Only the High Priest was allowed to pass the curtain and enter the Most Holy Place, (Heb. 9:6-7). And then he was allowed to enter only once a year, on the Day of Atonement, in order to atone for the sins of the people during the previous year, (see Lev. 16).
The featured text above, Heb. 9:24, is contrasting Christ and His priesthood with that of the Mosaic system. Christ is God's last and eternal High Priest. He is far superior to the aggregate of all the high priests who served under the Law, (Heb. 5:5-10; 7:12-28; 8:1-6; 9:1-28). He, too, performs His sacred duties before God on behalf of Christians in a specially designated place. But whereas the Levitical priests functioned in the Tabernacle or Temple, constructed of earthly materials by human hands, Christ officiates "at the right hand of the throne of the Majesty in the heavens, a minister in the sanctuary, and in the true tabernacle, which the Lord pitched, not man," (Heb. 8:1-2). The Hebrew tabernacle, or later the temples of Solomon, Zerubbabel, and Herod, were only "a mere copy of the true one." That is, they were only weak physical reflections of that celestial Sanctuary where Christ represents His people unto God face to face.
But what is the practical significance unto us today of the superiority of Jesus' high priesthood and of the Sanctuary beyond the mere recognition of its place so far above the Mosaic prototypes? The answer to this most relevant question is well supplied in the following chapter in this statement, "Since we have a great priest over the house of God, let us draw near with a sincere heart in full assurance of faith," (10:21-22). Because Jesus is our perfect High Priest, we as Christians are endowed with an assurance that is full, such as no other religious people have ever had. In our faith we are confident that Jesus can represent us unto the Father until the end of this age and will, even then, present us unto His Father as acceptable children purified by His blood, clothed in His perfect righteousness, and sealed for salvation by the impression of His name upon our souls.
Hebrews 9:24 is an especially meaningful verse to every disciple of Christ, for it is pregnant with comfort, exhortation, and hope. As the Levitical high priest entered once each year into the Holy of Holies with the blood of animals to atone for the sins of Israel, Jesus as our superior High Priest "through His own blood ... entered the holy place [heaven itself] once for all, having obtained eternal redemption," (Heb. 9:12). Notice the significance of the word "eternal." The blood offered by the Mosaic priest was effective for only a year, but the blood offered by Christ in His priestly office is effective forever. This is because it was "His own blood," not the blood of bulls or goats, which could not atone for human sins, (Heb. 10:3-4). Having obtained forgiveness for our sins with His blood, Jesus presents us unto God as souls whom He will accept. Also, Jesus as our High Priest is an intercessor through Whom we may make our petitions to the Father with assurance that He will listen, consider, and grant them according to His will to our best interests.