Why is sin futile?

Psalm 119:118You have rejected all who stray from your decrees. They are only fooling themselves.

Proverbs 10:28The hopes of the godly result in happiness, but the expectations of the wicked come to nothing.

Proverbs 11:7When the wicked die, their hopes die with them, for they rely on their own feeble strength.

Jeremiah 13:10“These wicked people refuse to listen to me. They stubbornly follow their own desires and worship other gods. Therefore, they will become like this loincloth—good for nothing!”

A life of sin causes earthly and eternal separation from God. An eternity without God is the ultimate futility.