This is really a collection of short stories that are compiled as a memoir of Penn Jillette's life. The stories are supposed to be examples of his ten alternative commandments, but the point isn't always clear.
The book is framed with his argument that if one would even think twice about sacrificing their child if God told them to, or if one wouldn't tackle a nonbeliever and slap him silly to prevent him from spending eternity in hell, that person is an atheist.
The short stories are raunchy and profane, but they are all enjoyable. One had me laughing out loud. One made me cry. (Yes. "I laughed. I cried.")
His point that the atheist view of life is actually a beautiful one is well worth considering. If this life is the only life we have, we should cherish our family and friends and every day of our lives. We should be kind and helpful to everyone now because we're not going to get a second chance.