Martin Luther as history’s first tweeter? An ongoing legacy, 500 years later: Three artifact shows demonstrate how Luther’s legacy is also as relevant and immediate as a Facebook feed. The Morgan Library exhibition in New York, “Word and Image: Martin Luther’s Reformation,” includes an extensive display of Luther-related materials. An exhibition at the Minneapolis Institute of Art focuses on the cultural and historical context of the Reformation. And an exhibit opening Oct. 11 at Emory University in Atlanta examines the debates over the law, grace and salvation that animated Luther and his followers.