The sermons contained in The Challenge were preached to audiences in Madison Square Garden, the Manhattan Center, and the Felt Forum in New York City. In addition, these services were telecast either live or rebroadcast the next evening in twenty-one cities from Boston to Miami along the eastern seaboard. In addition, three of these sermons were preached at prime evening time on more than three hundred TV stations throughout the United States and on an additional sixty stations abroad. This book contains, with only minor editing, the ten sermons just as they were given. - Introduction.