noun (n)

• religious zeal; the willingness to serve God(noun.act)

  Synonym:
  cultism, devotion, veneration
  

  source: wordnet30
• the worship of idols; the worship of images that are not God(noun.act)

  Synonym:
  idol worship
  

  source: wordnet30
• The worship of idols, images, or anything which is not God; the worship of false gods.(noun)

  source: webster1913