How do we know sin is serious according to the Bible?

Sin is depicted in the Bible as a serious offense against God, fundamentally a failure to meet His standards of holiness. Romans 6:23 states, 'For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.' This shows that sin has eternal consequences, which underscores its seriousness. Furthermore, 1 John 3:4 clarifies that 'sin is the transgression of the law,' linking sin to God's moral demands. Understanding sin in this way compels believers to see its gravity and the great need for repentance and the sacrifice of Christ.