God cannot suffer - at least not as we do. It has some roots in Greek philosophy: if God is a perfect being, suffering would reduce that perfection, so God cannot suffer. More thoughtful theologians take the phrase in the sense of one of the confessions of faith that talks of God as being "without parts or passions" - he is not physical as we are, and not subject to "passions" in the sense of uncontrollable emotions that can take charge of us at times. God is not "emotional," if that word is used as some kind of weakness.