God help us

God help us is a way to warn people that they may be hurt or punished if they continue to do what they are planning. It is often said in a sarcastic way to nobody in particular, rather than directed at the person who might be at fault for the foolish act that is being planned. They may also say it in a more blunt way to the group of people who are organized in a group in order to do something that is risky.