Words and phrases that come to mind: Blasphemous, sacrilegious, undiplomatic, indiscreet to the point of being rude.
If the Bishop likes this art so much, then have it installed in his own home or rectory. It’s not necessary to subject the parish to his whims of unusual ‘art’. Don’t force feed your personal views to everyone else.
A Bishop who lies this art so much, has no business being a Bishop. Keeping this blasphemous and sacrilegious dreck private doesn't change that it is blasphemous and sacrilegious.