What law did those who died in flood transgress?
Romans 4:15 "
Because the law worketh wrath: for where no law is, there is no transgression."
Romans 5:13 "
(For until the law sin was in the world: but sin is not imputed when there is no law."
1 John 3:4 ".
...for sin is the transgression of the law."
If there was no law, then no one could be a wicked sinful person. If there was no law, then how did they know what was right and what was wrong, how could any distinction be made between who is righteous and who is unrighteous?
Again, Romans 5:13, Paul is writing about the time between Adam and Moses, and the fact sin was in the world until the law of Moses proves that law existed prior to the law of Moses. We know law (God's law, natural law, etc) existed from the garden of Eden.
Genesis 4:7 how could God warn Cain about sin if no law existed? 1 John 3:12 how could Cain's work be evil and Abel's righteous if no law existed to tell us what is right and what is wrong? For Paul says "
.... I had not known lust, except the law had said, Thou shalt not covet" Romans 7:7.
If no law existed, then did Cain commit a sin in Genesis 4:8-13? How could murder be wrong if no law existed about murder? What was he punished for if no law existed?
Was theft a sin before the law of Moses, Genesis 30:33? How could adultery exist and be sinful if there was no law against it, Genesis 39:9?
Hebrews 11:4 "
By faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he was righteous, God testifying of his gifts: and by it he being dead yet speaketh."
"
By faith Abel offered...…. a more excellent sacrifice"
Romans 10:17 faith comes by hearing the word of God.
This must mean that Cain and Able heard the word of God, i.e., God's law concerning what would be an acceptable or unacceptable sacrifice.
So for sin to exist and for a person to be a sinner, there must be:
1) a law over and binding upon that person
2) that person must transgress that law
....eliminating the man made idea of original sin.