Full Idea
God cannot have a notion of suffering if he has not experience it.
Gist of Idea
God must suffer to understand suffering
Source
Sextus Empiricus (Against the Physicists (two books) [c.180], I.163)
Book Reference
Sextus Empiricus: 'Against the Physicists/Against the Ethicists', ed/tr. Bury,R.G. [Harvard Loeb 1997], p.85
A Reaction
Christians like to portray God as suffering because of his son's horrible death. We can imagine experiences we have never had, and presumably God is better at that than we are.