This is a fun little catchphrase that every pastor keeps chambered. They use it after saying something they imagine was startling.
Common uses of this phrase in sermons include:
“I know what you’re thinking. Isn’t God supposed to be a loving God?”
“I know what you’re thinking. Pastor Ed, are you going to lecture me on the evils of alcohol?”
“Now I know what you’re thinking. Crazy preacher man spouting off at the mouth about the whore of Babylon and some such.”
“Now I know what you’re thinking. Pastor Mark, what do you mean I should tithe more than 10%?”
And the most common version:
“I know what you’re thinking: easier said that done.”
This psychic revelation is often followed by “I’m not here to lecture you” or “You’d better believe it.”