Old Testament Challenge, Volume 4 is titled Pursuing Spiritual Authenticity: Life-Changing Words from the Prophets. The goal of OTC is to discover the life-changing truths of the Old Testament and how we can apply them to our lives today. Based on Pastor John Ortberg’s OTC series at the New Community services of Willow Creek Community Church, this resource will enable churches to raise the level of biblical literacy and understanding among its congregation.