Foxe's Book of Martyrs:

Foxe's Book of Martyrs is a book written by John Foxe that details the persecutions of the saints of God caused by evil men.  It will show you the brutality and evil that is in the hearts of men who claim to be religious and/or Christians.  Every person who calls themselves a Christian needs to read this book to get an understanding of early church history.  It will open your eyes and help reveal the difference between the people of Christ-less religions and the true children of God...