A. Seeing then that we have a great High Priest: The idea that Jesus is our High Priest was mentioned before (Hebrews 2:17 and Hebrews 3:1). But now the idea will be developed more extensively.
B. Seeing then: The writer to the Hebrews calls attention to the specific, unique character of Jesus as our High Priest.
C. Let us hold fast our confession: It is wonderful to know we have a High Priest, and how unique and glorious He is. It is even greater to know He passed through the heavens, that He ascended into heaven, and now ministers there for our sake. Both these truths should encourage us to hold fast our confession.
Based on the Enduring Word Bible Commentary by David Guzik.