Take one article of faith at a time and focus completely on that article until it is memorized to satisfaction. Have the students read it out loud, and repeat it out loud in the class without looking at the words. Do this daily or as much as possible.
Write the article of faith on a poster board. Write the article of faith again, on another poster board, but sporadically include blanks for words. Write the article once again, on another poster board, and include even more blanks for words.
Be creative and draw pictures instead of blanks or words. Show the posters one by one to the class and have them read it out loud, requiring them to memorize the words for the posted blanks.
Go online to the Articles of Faith Memory Quest game. Have the students go through the articles of faith putting the missing words in the proper blanks. Test their knowledge by having them repeat the articles without looking at the words.