Yes, this would be a difficult word for many. The word basically means an irreverence for anything sacred, so the very definition of the word makes this one tricky. However, it is not spelled sacRELIGIOUS -- it is spelled sacRILEGIOUS. The E comes after the L. Also, the correct spelling contains leg, which is a real word. The incorrect spelling contains lig, which is NOT a word.

Have read that this is the case because most associate religious with the this adjective and spell it sacrreligious...

this werd iz easie two spel, peepul. ewe just half too sounde itt owt.

Did you know that bookkeeper (or bookkeeping) is the only word in the English language that has 3 consecutive pairs of letters?

Ack! When people connect religion to this word, it is easy to see how we butcher this one!

I normally am a very good speller (I know I misspell a lot in my posts, but it's almost always because I just don't take the time to proofread before hitting the submit button), b ut I have to admit that I would tend to spell sacrilegeous as sacriligious, or even as sacreligious, even though I know that the word is based on sacrilege. The whole association with religion really throws one off psychologically with the spelling of this word.