During 1956, two years after his retirement on December 31, 1953, Bader wrote his first and only book -
Evangelism in a Changing America (The Bethany Press, 1957). In the introduction, David S. McNelly wrote, "He has outthought, outworked, and outloved his contemporaries, to turn the tide of religion in America towards a great revival. His passion for evangelism, his zeal for ecumenicity, his compassion for the misguided, and his love on behalf of the unlovely, as well as his concern for the unconcerned, has excelled in every circle on the American scene. Dr Bader has moved across America and many kindred nations in the last quarter of a century, breathing the evangelistic spirit of life into the church, making bold the Great Commission of
Jesus Christ. ... today many patterns of evangelism used by the American church were pioneered, perfected and promoted first by Dr. Bader. He … has done as much as any living man to establish a climate for evangelism in America today." Bader had been a pioneer in promoting the idea that evangelism and ecumenism went hand in hand, as opposed to being mutually exclusive. The final chapter of the book,
Evangelism Together, stresses that, although there is a place for churches to focus on their own evangelism, some evangelism must be done together. Bader claimed that this idea was formed from his own lived experiences. ==Retirement==