καὶ ἐπειδάν μοι μὴ δοκῇ, τῷ θεῷ βοηθῶν ἐνδείκνυμαι ὅτι οὐκ ἔστι σοφός.
I don’t know how to read ὅτι here. After (ἐπι-/ἐν-)δείκνυμι (in the middle as well, LSJ) we have the dependent statement
in part. But here I have ὅτι as well. Should I just translate it as “…,helping God, I show that he is not wise.”?
The LSJ also says there “also ἐ. ὅτι” and includes a reference to this passage. That’s how I read it as well.
I guess it’s grammatically possible to read it as “I show myself as helping the god, because he is not wise” but that doesn’t seem to make sense together with the επειδαν clause.
Can’t see where the problem is if you read the previous sentence too.
“ταῦτ᾽ οὖν ἐγὼ μὲν ἔτι καὶ νῦν περιιὼν ζητῶ καὶ ἐρευνῶ κατὰ τὸν θεὸν καὶ τῶν ἀστῶν καὶ ξένων ἄν τινα οἴωμαι σοφὸν εἶναι: καὶ ἐπειδάν μοι μὴ δοκῇ, τῷ θεῷ βοηθῶν ἐνδείκνυμαι ὅτι οὐκ ἔστι σοφός.”
Bit of a scratch translation as per usual 
So even now I go around looking and searching as the god (asked? said?) among both the citizens and the foreigners if I think someone’s wise (who I think is wise). And whenever he (the citizen of foreigner) doesn’t seem (to be wise), I show that he is not wise, helping (“thusly” maybe) the god.
I understand, Ireney. Thank you.
I did not notice that addition and reference. Thanks.