Hebrews 9 - NKJV

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 Jesus Spirit purification
And for this reason He is the Mediator of the new covenant, by means of death, for the redemption of the transgressions under the first covenant, that those who are called may receive the promise of the eternal inheritance.
Hebrews 9:15 law Savior mediator

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 sin sacrifice salvation