Since then we have a great high priest who has passed through the heavens, Jesus, the Son of God, let us hold fast our confession. [Hebrews 4:14 ESV]
What comes to mind when your hear the title High Priest? I think of the person who was designated to enter the Holy of Holies, the inner sanctuary of the Jewish Tabernacle where God dwelt. To get there the priest had to pass through other rooms. This seems to be what is referenced here.
The High Priest was the one who interceded, before God, on behalf of the Jews. He made offerings and prayers for himself and for them. In that sense Jesus is presented as a great high priest. One who has, metaphorically, passed through the outer rooms and entered God's presence.
The metaphor breaks down, all of them do, if one tries to read it literally. The central point is that Jesus, one not qualified by Mosaic law to be a priest (he was not a Levite), became the last High Priest. This is what we confess. We no longer need a human priest. Our priest is in heaven.
Heaven, the holiest of holies, is accessible because of you Jesus. We give you thanks.
... this devotion is part of a series about the book of Hebrews.