The one true church cannot teach error or Christ would be teaching errorFaith can also come by reading. But as you mentioned earlier, we are to go out and be a light in both word and deed!
There are many false prophets and false teachings, even from within the church, which is why it is good to search scripture like the Bereans.
Christ and the church are one acts 9:4
Jn 8:32 16:13 Lk 10:16