Q.28: How does Christ execute the office of a priest?
A. Christ executes the office of a priest in His once offering up Himself a sacrifice to satisfy divine justice and reconcile us to God, and in making continual intercession for us.
How much more shall the blood of Christ, who through the eternal Spirit offered Himself without spot to God, cleanse your conscience from dead works to serve the living God? Hebrews 9:14
So Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation. Hebrews 9:28