Hebrews 2:3
how shall we escape the penalty for neglecting a salvation which was originally proclaimed by the Lord himself and guaranteed to us by those who heard him,
Hebrews 9:28
so Christ, after being once sacrificed to bear the sins of many, will appear again, not to deal with sin but for the saving of those who look out for him.
Hebrews 10:26-29
For if we sin deliberately, after receiving the knowledge of the Truth, there is no longer any sacrifice for sins left,
Hebrews 12:25
See that you do not refuse to listen to His voice. For if they failed to escape, who refused to listen to their instructor upon earth, much less shall we escape, if we discard Him who speaks from heaven.