This might not be the most thorough economics text, but it's without contest the most fun. Vic Lockman's lifetime career as a cartoonist and biblical thinker stands him in good stead as he introduces concepts like the orignation of money as a form of exchange, what the Bible has to say about taxation, the unscriptural foundation of Communism, etc.
Even if this isn't the most thorough book on the dismal science you'll read, it's pretty thorough as an overview. How economies operate, what they are, and the proper Christian attitude toward them are all explored through engaging text, Bible references, and funny drawings. If Hayek had known you could discuss principles of supply and production with little mouse characters he might have triumphed publicly over Keynes and we'd all be better off.
What's particularly great about this book is its appeal to all ages. Adults will find it informative, high schoolers will find enough real information to not be embarassed seen reading it, and even younger kids may be intrigued enough by the artwork to find out some things about finances and economic theory.
The constant comparison of practice and theory to the Word of God helps keep things in perspective. There are some pretty advanced concepts involved (what is a dollar? can governments create jobs?) but Lockman takes them all in hand without ever sounding condescending or missing the point of an argument. Don't use this as your sole economics text, but by all means use it as an introduction to a more comprehensive book like Hazlitt's Economics in One Lesson or Kirk's Economics: Work and Prosperity. Or just read it for fun.