14. What was Sodom's sin?
This was the iniquity of thy sister Sodom ... they ... committed abomination before me. Ezekiel 16:49-50
Whosoever shall not receive you, nor hear your words ... Verily I say unto you, It shall be more tolerable for the land of Sodom and Gomorrha in the day of judgment, than for that city. Matthew 10:14-15
Seeking sex with angels, fornication, and going after "strange flesh"
And there came two angels to Sodom. Genesis 19:1
Pride, wealth, laziness, and ignoring the needs of the poor
Hear the word of the LORD, ye rulers of Sodom ... ye people of Gomorrah ... Learn to do well; seek judgment, relieve the oppressed, judge the fatherless, plead for the widow. Isaiah 1:10-17
Adultery, lies, and general immorality
I have seen also in the prophets of Jerusalem an horrible thing: they commit adultery, and walk in lies: they strengthen also the hands of evildoers, that none doth return from his wickedness: they are all of them unto me as Sodom, and the inhabitants thereof as Gomorrah. Jeremiah 23:14
Living ungodly, filthy conversation, unlawful deeds.
Turning the cities of Sodom and Gomorrha into ashes condemned them with an overthrow, making them an ensample unto those that after should live ungodly; And delivered just Lot, vexed with the filthy conversation of the wicked: (For that righteous man dwelling among them, in seeing and hearing, vexed his righteous soul from day to day with their unlawful deeds;) 2 Peter 2:5-9