Hebrews 12:18-19

12:18 For you have not come to something that can be touched, to a burning fire and darkness and gloom and a whirlwind 12:19 and the blast of a trumpet and a voice uttering words such that those who heard begged to hear no more.

Hebrews 12:25

12:25 Take care not to refuse the one who is speaking! For if they did not escape when they refused the one who warned them on earth, how much less shall we, if we reject the one who warns from heaven?