Joseph Lied, Adam Died

Encyclopedia of Joseph Smith’s Teachings, p. 237; “Fallen Man. There has been no change in the constitution of man since he fell. (Joseph Smith, History of The Church of Jesus Christ of Latter-day Saints, 7 Vols. 2:17)” – edited by Larry E. Dahl and Donald Q. Cannon [Salt Lake City: Bookcraft, 1997]

Romans 5:12; “Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned.”

I honestly don’t get how Smith slept at night. Everyone in the entire world has become worse and worse over time. What is the explanation for the Flood if Joseph’s theory is correct?