Ever since Plato philosophers have used dialogue to convey ideas. How To Be Your Own Selfish Pig isn't exactly philosophy and it isn't exactly straight dialogue, but it is an excellent introduction to common ways of thinking and understanding the world. Susan Schaeffer Macaulay (daughter of the illustrious Francis A. and Edith Schaeffer) presents worldviews through conversations with visitors and residents of her father's L'Abri ministry.
Some people think the Bible is just a bunch of fairy tales. Others feel many or all paths lead to salvation. There are nihlists who do whatever they want with never a qualm of conscience (or so they say), scientists who trust technology and the tenets of evolution to guide human progress infallibly, humanists who believe human behavior can be modified for compatibility through psychological manipulation.
All these views and more are expressed in Macaulay's smart book, each one expressed by real people who've actually sought truth and meaning through means other than the Christian gospel. Macaulay subjects each perspective to biblical scrutiny, showing why they are insufficient to explain human existence, the meaning of life, and spirituality, and why the Christian worldview ultimately does explain all those things.
Funny illustrations offer a lighthearted element, because while there's plenty to enjoy, there's a lot of really sad stuff, too, as real individuals describe how they ruined their lives pursuing secular ideas. This isn't a worldview text per se, but it does serve as an excellent introduction for readers of all ages. It's also a great refresher for those who've studied philosophy, reminding them that ideas and thinkers really do affect people, often destructively.
If you really want to know How To Be Your Own Selfish Pig, this isn't the book for you. While you could piece together your own program to achieve self-centered odiousness from the stories included, the point is not to promote secular ideals but to show how they're destructive and result only in isolation and pain. The only alternative—Christ's grace—is clearly presented throughout.