Did the flood really happen? Well there may be an actual event associated with this story but given the plagiarism, it seems unlikely.
Were Sodom and Gomorrah real cities? Considering the smoldering remains have never been found, it seems likely that their existence is also fictional as would also be their destruction. Pompeii was covered by the debris of a volcano and it was still found.
Did Jesus exist? The record of his life certainly exists but that record is highly suspect as ever being the actual chronicle of a real person. It has been edited, embellished and corrupted by many scribes and political factions before it was presented to you and I.
If Jesus ever existed he was just a man as the scriptures also bear record in many places of his true nature. Though many stories of people have left indelible marks on the world for their great works, that of Jesus being no exception.
But was Jesus infallible? The record of Jesus can be scrutinized and many of his own faults found therein but as to the real man Jesus (if he existed) given the human condition it is likely he had faults also.
But don't we all? But some people rise above their faults and become illustrious and revered for their good deeds.
The apocrypha write of Jesus being a mischievous child...
Though, good deeds can, "cover a multitude of sins".
So it comes down to the idea that there was no Adam and Eve in the Garden, there was no great flood, there was no Sodom and Gomorrah and there was no Jesus but the remnants of the morality of these tales leave ideals to be reckoned with.
If there was no Adam and Eve, there was no original sin, the was no great flood and murder of humanity, so there likewise, was no God or devil to blame... and there was no savior of the world either, other than stories created solely in the imagination of poets and philosophers. Salvation is built upon a myth.
But is there still evil in this world? Yes, there most certainly is...
Science, reason, rationale and conscience are our saving grace, not some person or god that we follow blindly because it seems like the right thing to do.
Proverbs 14:12 (KJV)
12 There is a way which seemeth right unto a man, but the end thereof are the ways of death.
Comment: As there is evil, there is also truth, light, many kinds of love, understanding, acceptance, tolerance, goodness, kindness and grace.
Rather than fabricated events, a deity or person whose existence and life is fictional, perhaps an evidentiary approach to wisdom is more in keeping with "truth".