""The Duty of Christians in the Present Crisis: A Letter to a Christian Brother"" is a book written by Henry Grattan Guinness in 1861. The book is a call to action for Christians in the midst of a crisis. Guinness argues that Christians have a duty to take a stand against the prevailing cultural and political trends of their time. He believes that Christians must be willing to speak out against injustice, oppression, and immorality, and to work to...