Hebrews 2:3
how shall we escape if we neglect so great salvation, which, commencing at the beginning to be spoken by the Lord, was confirmed unto us by those who had heard him;
Hebrews 6:6
and yet have fallen away: for they crucify again to themselves the Son of God, and expose him to public infamy.
Hebrews 9:28
so Christ having been once offered in sacrifice to bear the sins of men, will appear the second time without sin, to those who expect him, for their salvation.
Hebrews 10:26-29
For if we sin wilfully after we have received the knowledge of the truth, no more sacrifice for sins remaineth;
Hebrews 12:25
Beware that ye reject not him that speaketh: for if they escaped not, who rejected him, that upon earth spake by divine influence, much more shall not we escape, if we turn away from him who speaks from heaven: