The New Oxford American Dictionary describes the word catechism as 'a summary of the principles of Christian religion in the form of a series of questions and answers'. I love the simplicity of St Ninian's Catechism which is taken from the book Celtic Fire by Robert Van de Weyer:
Question: What is best in this world?
Answer: To do the will of our Maker.
Question: What is his will?
Answer: That we should live according to the laws of his creation.
Question: How do we know those laws?
Answer: By study - studying the Scriptures with devotion.
Question: What tool has our Maker provided for this study?
Answer: The intellect, which can probe everything.
Question: And what is the fruit of study?
Answer: To perceive the eternal Word of God reflected in every plant and insect, every bird and animal, and every man and woman.