They fell from grace, and it became our fall as well. Since then, every man has inherited Adam's sin, and the depraved desire to be independent of God. Although we are born sinful, we remain entirely responsible for every act of sin we commit. Sin is falling short of God's righteous standards, and the wilful transgression of His commandments. Humanity has fallen from its divine purposes.
Sin has eternal consequences.
Without Christ, we will experience eternal conscious torment in hell forever. Hell is as real as heaven. A just and holy God must punish sin. He will not compromise with and does not condone sin. We are hopelessly trapped in sin by nature and by conduct.