Word 1:Sacrilege (SAK ruhlij)
This word is a noun.
Meaning: An act of treating a holy place or object in a way that does not show proper respect.
Example Sentence: It was considered a sacrilege for non- Brahmins to touch the statues.

Word 2:Sacrilegious (sak” ruh LIJ uhs, sak” ruh LEE juhs)
This word is an adjective.
Meaning:Grossly irreverent toward what is held to be sacred.
Example Sentence: In the past it was sacrilegious for women to enter the domain of men.

The difference between the two words is the part of speech they belong to. Since one is a noun and the other an adjective, you need to decide the usage depending on the need of the sentence.

Example Sentence using both words:
The acts which were sacrilegious in the eyes of his mother were hardly a sacrilege to him.