not walk on water

An allusion to the Gospel story in which Jesus walks on water.

1. To not be above moral reproach; to not be a saint. Look, I know she can't walk on water—she certainly has her share of character flaws. But I still think her policies are sound. I just don't know why you let him get away with these sorts of things. He doesn't walk on water, you know!

2. To not be able to do something extraordinary or impossible. With the failure of his latest company, it's becoming clear to investors that the business wunderkind doesn't walk on water. How on earth do you think I'll be able to get all this done on time? I can't walk on water!