How do we know that God’s word is authoritative and serious?

Hebrews 4:12 states that the word of God is quick and powerful, sharper than any two-edged sword, capable of piercing the soul and spirit. This underscores the authority of God’s word and its ability to discern thoughts and intentions. Throughout scripture, whenever God speaks, it carries divine authority and a serious message for His people, as illustrated by His interactions with Moses and the Kohathites in Numbers. This authority leads to life for those who heed it and death for those who disregard it.