Iconostasis, edit 2: Caleb, Mark, Joseph, Matt, Achebe

[Magpie]

RiverNotch, this is a fascinating short poem that you've got here but ultimately I am unsure of what you mean by it. It seems to be filled with symbols which to me could be interpreted in various ways. I'm not sure how much of a critique I can offer in terms of alternative word suggestions etc when I don't know your exact meaning, so instead I suppose this is more of a thought process I am going through as I go through your poem and hopefully this may be of some help to you.

BASILICA  -- I am taking the title to be symbolic of 'an important place of worship' or 'a church with great importance'. I think Basilicas are all catholic (damn I should have checked that first) which could indicate that this is specifically a reference to catholicism. My actual first thought upon seeing the title was 'St. Peter's Basilica', but I tried not to let that sway me towards anything, even though I could possibly see other parts of the poem that would suggest a connection with St. Peter.

Piety turns -- The line break makes sense here instead of having it all on one line.
the heart to stone. -- As an opening statement it is quite powerful and sets the whole premise for the poem. As a symbol a 'heart of stone' could be seen as cliche, but I think that there are other more important factors at play here, so for me its inclusion is fine.

Let me cover this rock -- Because of the use of 'stone' in the line before this could be seen as a continuation so it would be 'Let me cover this stony heart...' However you could also be talking about a cave, a building, the planet earth. Perhaps the ambiguity is good and what you were going for. Also 'rock' for me is the possible connection with St. Peter whose name means 'rock'... I am trying to tell myself that this is all just a coincidence because of my initial thought about 'Basilica'. However because the etymology of the word 'Peter' and it's roots is torn between 'stone' and 'rock' which could be seen in different ways, then I'm also thinking if you may be including both 'stone' and 'rock' as a way of covering all aspects. Yeah I know... I think way too much. 
in gold leaf, in the delicate -- gold leaf as an architectural feature is what a Basilica would be decorated with and also as a symbol this would work, denoting a place of importance.
browns of flesh, in flecks -- the use of 'brown' flesh could be seen by some as an exclusion of some peoples, others may see it as a compromise that really means all peoples. The thought the keeps on cropping up for me is people of the Middle East area, ie Jesus country. If this is the 'delicate brown flesh' colour that is intended could the use of 'Olive skinned' be of any help in defining. Yet again, it could be of symbolic meaning??
of black and rich azure -- -- 'flecks of black' I can see in architectural/decoration terms but it's meaning or significance escapes me. The use of the word 'flecks' seems very specific, like you may have wanted a word that describes a visual effect at the same time as possibly having a negative connotation like in the way that you can 'stain' wood.
let it not remain gray, -- Could this be a separate sentence starting here?? As it stands the whole thing is two sentences and the second sentence is one hell of a long sentence but is it too long?
empty, almost modern, -- the use of 'modern' here is interesting. 

ultimately the kinder home to moss -- what is a kinder home to moss? A rock? Something natural? Technically and biologically it would be somewhere constantly moist/damp and with not too much sunlight. But 'moss' is obviously a symbol, but a symbol of what... I'm unsure. They have no seeds, they grow in places that other plants would never grow - which is in some ways a 'compromise'. Bearing in mind the title I could possibly see moss as pious pilgrims going to places like St. Peter's Basilica, the pious life could easily be seen as a life of compromise...
which knows only compromise.

I don't envy the fact that you have to read what I just wrote, I never checked over it again, it may be crazy and nonsensical and other things I'm not sure of. What is for sure though is, it is way too much for 'mild critique' so I apologise if it was a bit too much, it does seem to happen a lot.

Cheers for the read, I have enjoyed the various paths of discovery that it has taken me,

Mark