Comment 14 by alphonsus :

Not really. The ability to "work it out for themselves" is an expression of what Christianity understands as the Natural Law,

Christianity "understands" nothing when it comes to nature. It has nothing at all to say about that natural world whatsoever. Neither do other religions.

in other words people are endowed with the natural ability to arrive at the truth through their use of reason,

Indeed. They have been "endowed" just as other creatures have been endowed with a moral sense by the slow process of evolution. This is not only well understood and researched, it is by a country mile, the best explanation we have for morality. It fits.

as beings created in the image of God.

Unfortunately there is no evidence whatsoever for whatever is meant by god. None at all. It is an unnecessary, non-parsimonious, non-explanation to say that god poofed morality into us, even more so given that we have good evidence that morality is part of our evolutionary heritage. God explains nothing. He is superfluous and there is no reason to believe it exists.

Unaided reason can't always arrive at the full truth,

Unaided? What's that? Society and communities aid us in bringing about the Zeitgeist and we all have a sense of what is wrong and right based upon fairness which is probably derived from our evolutionary heritage.

but in principle

There is no principle to what you are writing. None at all.

the truth revealed by God (through the bible and the church) is the same as that arrived at by reason.

God (who doesn't even exist) has revealed ... nothing.

Faith and reason, as the church has been saying for a long time, are not contradictory but complementary pathways leading to the truth.

The church has been declaring by fiat that they are one and the same. You may have swallowed that but the merest scrutiny should disabuse anyone of this nonsense. The enlightenment which trashed the contents of the bible and resigned it to myth status has steadily been showing that the "truth" is what we can demonstrate with a degree of repeatability and independence. The only "truth" left over the church is found in perverted and corrupted (theological) philosophy.