I had the idea of turning the image inside out -- instead of the face appearing on top of the cross, framing the face with multiple copies of the cross. I used the smudge tool on a copy of the cross to erase the face, then copied and flipped it to form the frame. I then selected the face and expanded it to fill the frame, adding shadows to suggest eyes. I selected a section of the face and used it to define a pattern and then filled a layer with it to form the background.