Martin Luther (1483–1546) was a German theologian and one of the most influential figures in the Protestant Reformation. Some of Luther’s best-known works are the Ninety-Five Theses, “A Mighty Fortress Is Our God,” and his translation of the Bible into German.  Alister McGrath (PhD, University of Oxford) is the Andreas Idreos Professor of Science and Religion at the University of Oxford, president of the Oxford Centre for Christian Apologetics, and senior research fellow at Harris Manchester College in Oxford. He is also a noted author and coeditor of Crossway's Classic Commentaries series. J. I. Packer (1926–2020) served as the Board of Governors’ Professor of Theology at Regent College. He authored numerous books, including the classic bestseller Knowing God. Packer also served as general editor for the English Standard Version Bible and as theological editor for the ESV Study Bible. J. I. Packer (1926–2020) served as the Board of Governors’ Professor of Theology at Regent College. He authored numerous books, including the classic bestseller Knowing God. Packer also served as general editor for the English Standard Version Bible and as theological editor for the ESV Study Bible.