How does anyone know what Christianity teaches? Different Churches
have different ideas about the answer to this, which is why
they disagree about the answer.
So what are the possible answers?
They may be summarised as certain writings, certain oral traditions,
and the opinions of certain men (not women). Again different
Churches assign different weights to these sources and of course
there is scope for disagreement as to which writings count as
authoritative, which traditions count as authoritative and which
which men to regard as authoritative.
To untangle the mass of different answers that different Churches
have adopted, let's take a look at the fill range of possible
authorities, and how reliable they are: