They be blind leaders of the blind.
Blind guides
The bankrupt who asks a bankrupt to set him up in business again, is only losing time. The pauper who travels off to a neighbouring pauper, and begs him to help him out of difficulties, is only troubling himself in vain. The prisoner does not beg his fellow-prisoner to set him free. The shipwrecked sailor does not call on his shipwrecked comrade to place him safe ashore. Help in all these cases must come from some other quarter. Relief in all these cases must be sought from some other hand. It is just the same in the matter of cleansing away your sins. So long as you seek it from man, you seek it where it cannot be found. (Bishop Ryle.)
Mutual ruin
The falling of both together will aggravate the fall of each; for they that have thus increased each other’s mutual sin will mutually exasperate each other’s ruin. (M. Henry.)