How do we know that hell is real according to the Bible?

Jesus speaks of hell in stark terms in Mark 9, mentioning that it is a place of unquenchable fire and eternal punishment. The descriptions of the 'worm that never dies' and 'the fire is not quenched' serve as warnings of the serious consequences of sin and the need for repentance. These vivid portrayals compel Christians to take the topic seriously and urge others to flee from it through faith in Christ. Hell, as mentioned in the Bible, is not just a figurative concept but represents the ultimate separation from God, highlighting the urgency to accept His mercy while there is still time.