Hebrews 2:2

2:2 For if the message spoken through angels proved to be so firm that every violation or disobedience received its just penalty,

Hebrews 4:6

4:6 Therefore it remains for some to enter it, yet those to whom it was previously proclaimed did not enter because of disobedience.

Hebrews 4:11

4:11 Thus we must make every effort to enter that rest, so that no one may fall by following the same pattern of disobedience.