Born in Brooklyn, New York, Walls attended high school and college seminary before pursuing a career in business. He studied business at Baruch College and completed his degree at Concordia College. After beginning his career at an accounting firm, he joined a chocolate manufacturing company and at age twenty-six was appointed vice president of operations. In 1992, he founded his own chocolate company, Sweet Roots, Inc. which sells the only chocolate bar using exclusively African cocoa and produced by an African- American.
Walls worked with Greyston Bakery to bring its cakes and tarts to the White House in 1993. In 1995, he joined Greyston as a marketing consultant and in November 1997 became CEO of the Bakery, adding vice president of Greyston Foundation in January 2000. A core ingredient of Walls's life and career is his spiritual practice. He encourages employees to actively bring their whole selves to work, including their cultural and spiritual selves. He has spoken extensively throughout the country on the topics of social ventures, social purpose businesses, spirituality in the workplace, and business development in the inner city. He is active in service to the community, serving on eight local and national boards. Walls resides in Yonkers with his wife, Cheryl, and three children.