believe of

believe (something) of (someone)

To accept that a statement about someone is true. I can't believe these lies of Cheryl—I have always known her to be a very reputable businesswoman.
See also: believe, of
Farlex Dictionary of Idioms.

believe something of someone

to accept a statement about someone as truth. What a terrible thing for Jill to do. I can't believe it of her. I can believe anything of Max. He's such a conniving person.
See also: believe, of
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • believe (something) of (someone)
  • lie like a trooper
  • not believe a word of it
  • know of
  • know of (someone or something)
  • delude (someone) with (something)
  • delude with
  • porkies
  • porky
  • be a shining example (of someone or something)
References in periodicals archive
Hence, I may have sufficient reason to believe of a set of propositions that I respectively had (and possibly still have), have or will have sufficient reason to believe it.
In other words, let it be the case that I presently have sufficient reason to believe of a particular P-relevant set of propositions E* and a particular time t* that (E**) (1) I have sufficient reason to believe that E* at t*,
"P and I will believe that not-P": diachronic constraints on rational belief