In order to get into the bedroom upstairs, you need to open the cabinet in the back hall downstairs. To get the cabinet open, you need to have read the Iluminados 4:3 verse that is found upstairs on the table. That will tell you that the cabinet lock is crops, pig, and baby.
That will get you the marble that you need to put in the door upstairs. I found it easiest to turn it to find the “sharpest” edges to get it to look like the church insignia. Once you can sort of pick out the shape of the lower legs, then you can just turn it right-side up.
See below the screenshots for a video.
The Iluminados 4:3 verse is upstairs on the hall table.
Crops, pig, baby.
Turn it until you see the “sharper” design and then start looking for the lower legs. When you can discern those, turn it right-side up.
Video: