rock/shake (something) to its foundations

to damage or change an organization or a person's beliefs very much.

Allegations of scandal and abuse have rocked the party to its foundations.

The ideas seemed to make sense, but shook the foundations of her own Christian beliefs.

• you can bet on it
• you can bet your bottom dollar
• you can bet your life
• you can kiss goodbye
• you can kiss something goodbye
• You can lead a horse to water.
• You can lead a horse to water but you can't make him drink.
• You can lead a horse to water but you can't make it drink.
• you can say that again
• You can say that again!
• You can talk!
• You can't judge a book by its cover.
• You can't keep a good man down.
• You can't keep a good woman down.
• You can't make an omelette without breaking eggs.
• You can't make a silk purse out of a sow's ear.
• You can't make bricks without straw.
• you can't miss it
• You can't say fairer than that.
• You can't teach an old dog new tricks.
• You can't win 'em all.
• you could cut the atmosphere with a knife
• You could have heard a pin drop.
• You could have knocked me down with a feather!
• You could have knocked me over with a feather!