Asher Kelman
OPF Owner/Editor-in-Chief
This one is developed from a single raw capture entirely in LR5 using exposure/contrast/highlight/shadows/whites/blacks/clarity/saturation sliders. No other processing has been applied, no brushes, no filters, no noise reduction, no sharpening; nothing. The end result speaks for itself. I hope you will enjoy it. Please feel free to C&C.

Here is the version processed in Topaz Clarity. Looking more like it.

Cem,
Most of what I was looking for is here. Bravo! Yes, Topaz is a smart filter and well deserved here. But there's also some bare truth to the first picture you made. I do not want to say goodbye to that sense of truth.
When I achieve a stunning improvement like this, I put the picture aside for a while. Then I'd try to decrease the fraction of this sparkling layer to the minimum needed to mature the picture from the more earthy original. I might use a mask to selectively use more of the effect in some elements than others, so ranking visually what I thought is important in reading the picture the way I think it should speak to us.
So, for my part, this is the most personal and creative stage of presenting the picture, the rationing of the processes we use to elevate some parts over others. In this particular case, I'd consider pulling back on the ceiling as it's too open, make the end only barely obvious and bring back the original texture on the right hand wall. That way, the window light dominates to make the picture representative of god's light entering the Abbey generously but not disclosing everything equally. The church also has mystery and that has to be preserved.
Asher