What does the Bible say about God speaking from heaven?

In Hebrews 12:25-29, the writer warns us to heed the voice of God that speaks from heaven, contrasting it with the voice of God that spoke at Mount Sinai. This warning underscores the seriousness of our response to God's revelation through Christ. Just as those who rejected God's word at Sinai faced dire consequences, we are warned that neglecting the message of salvation through Jesus has even greater repercussions. The emphasis is on belief and obedience; thus, those who hear must genuinely respond and not merely listen without acting.