"Attacking bad books is not only a waste of time but also bad for the character. If I find a book really bad, the only interest I can derive from writing about it has to come from myself, from such display of intelligence, wit and malice as I can contrive. One cannot review a bad book without showing off."

Next Quote

If I profess with loudest voice and clearest exposition every portion of the truth of God except that little point which the world and the Devil are at that moment attacking, I am not confessing Christ, however boldly I may be professing Christ. Where the battle rages, there the loyalty of the soldier is proved, and to be steady on all the battlefield besides, is mere flight and disgrace if he flinches at that point.

— Martin Luther