accept (something) as gospel
To believe that something is absolutely true without any hesitation or reservations. When we're growing up, we accept what our parents tell us as gospel. The beloved professor's opinions on the subject are accepted as gospel by his students.
accept a wooden nickel
To accept something that proves to be fraudulent or deceitful; to be swindled or conned. Primarily heard in US. I'm done accepting wooden nickels—capricious women who say they love me, then get bored and decide I'm not worth their time. My husband is a wonderful man, but he has about as much business sense as a grade-schooler. If I had let him accept all the wooden nickels offered flaky customers have tried to peddle on us, we'd have gone bankrupt years ago.