2 Chronicles 7:14
If my people, who are called by my name,
shall humble themselves,
and pray, and seek my face,
and turn from their wicked ways; ,
then will I hear from heaven,
and will forgive their sin,
and will heal their land.
Oft cited, but the theology of the Old Testament promise isn’t the same as what happens when a society is Christianized. (The latter is better, not worse.)