Thomas Paine, a deist and one of the American founding revolutionaries after Ben Franklin invited him to immigrate to the restive colonies, in this book pillories organized religion.
He does so by dissecting both old and new testaments of the bible and pointing out the hypocrisy of the established clergy. The book was very controversial in its time and landed the publishers in hot water.
Paine, like Thomas Jefferson, was no atheist but had no use for organized religion or its doctrine. The book makes a perfect gift, and I recommend it to everyone, especially teenagers and young adults in the process of figuring out what they believe.