I will go down to see whether they have done altogether according to the outcry that has come to me. And if not, I will know.”
Genesis 18:21

God had to see Sodom for himself because He respects the rule of Law and due process. God keeps His own rules for the sake of His name and His creations. No man or city may be condemned without a trial and two witnesses before a qualified and impartial judge.

What was the "cry of Sodom and Gomorrah" in Genesis 18:20-21? Probably the blood of their innocent victims crying out from the earth, like Abel's before them and the martyrs of the Beast in Revelation.

What were Sodom's great sins? Violence against the weak, injustice to sojourners, and sexual immorality, at least. How do we measure up?