I can't believe it/that/this
This information is so shocking or implausible as to be unbelievable. A: "Did you hear that Amanda got the promotion?" B: "Yep, and I can't believe it. I know I'm more qualified for it than she is!" Are they really closing McCauley's after 40 years? I can't believe it!
I can't believe (that)!
That is unbelievable! Tom: What a terrible earthquake! All the houses collapsed, one by one. Jane: I can't believe that! Bill: This lake is nearly two hundred feet deep. Sue: I can't believe that! Bill: Take my word for it.