I don't recall seeing a 3E write-up for Andral's faith anywhere, but a few things can be extrapolated from "I, Strahd" and other 2E sources:
- Andral is Lawful Good, judging by the 2E assumption that clerics had to share the
exact alignment of their deity; the Morninglord (at least in Ravenloft) is viewed as Chaotic Good. That, in itself, would help tell the two apart, as Andral's church was much more hierarchical and inclined to cooperate with secular authorities. (Granted, that's a lot easier when the secular authorities
aren't virtually all darklords....
)
- The longsword is a logical favored weapon for Andral's church. This can be inferred from the fact that Sergei von Zarovich (who'd been destined for the clergy up until his marriage-plans and subsequant murder derailed that) was trained in swordsmanship, even though his birth-order'd slated him for
peaceful Church responsibilities, his whole life. This wasn't just casual sparring either, as might be accounted for due to childhood fencing-lessons from a family's militant traditions; Strahd's brother once bested a dangerous bandit leader on a counter-raid led by his sibling.
- Both men and women were welcome within Andral's clergy, but at the time Barovia became cursed, none were permitted to wed. (This seems to have since changed in Material Plane Barovia, BTW, as a
married high priestess of Andral appeared in "From the Shadows".) The ranking cleric in Barovia at the time of Strahd's crimes was a woman, powerful enough to cast Raise Dead.
- Bloodline seems to have trumped experience-levels or simple seniority, in determining one's authority within the clergy. Before renouncing his calling to wed,
Sergei would have inherited leadership of the Church from the late High Priest Kir, even though he was only 27 (and evidently not even ordained yet, despite what some 3E products imply) at the time! Lady Ilona, another ranking clergy member from Strahd's day, was born to a noble family; the High Priestess in "From the Shadows" was the Queen-consort of Material Plane Barovia's King Barov IV.
- Andral's church evidently had its ups and downs, even before Strahd's crimes. Several sites in Barovia (and a few more in Borca, though they might or might not correspond to actual Material-Plane sites; we can't be sure how closely Borca recapitulates Barovia's old neighbor Borjia) were originally dedicated to Andral, but were later closed down and co-opted for military or other purposes.
- Like many Good-aligned faiths, the Church of Andral took responsibility for charitable works throughout their sphere of influence. Tatyana herself was an orphan, raised in the Church's custody. Lady Ilona's discussions with the still-living Strahd suggest she was well-accustomed to speaking up for the commoners' welfare, and using diplomacy to curb the excesses of grumpy military-minded noblemen.
- Despite its Lawful bent, forgiveness and compassion seem to have been a strong component of Andral's teachings. I don't recall the full list of inscriptions on the Holy Symbol of Ravenkind, but IIRC there were more of them that pertain to the merciful side of Lawful Goodness than to its crusading, judgemental side.
The fact Andral wasn't specifically a
dawn-god, as the Morninglord (actually a reinterpretation of Lathander from FR) is, would in itself make their creeds somewhat different in emphasis: the latter deity's emphasis on new beginnings and fresh starts would be absent. Note, too, that while Andral is the only Good-aligned deity from the Von Zarovich homeworld that Ravenloft's Barovians
remember -- not surprising, given that he was evidently the Von Zarovich family's patron god -- he's clearly not the
only such deity from their original world. Andral was probably part of a larger, now-forgotten pantheon (there are numerous references to "the gods" in the novels and 2E products, from before 351 BC) at one time ... and he may not even have been its chief deity, at that, though he was clearly the predominant deity within historical Borjia (the Balinoks [later "Barovia"] included).