Dr. Sills joined Southern Seminary after serving as a missionary in Ecuador. While with the International Mission Board, he served as church planter and general evangelist among the Highland Quichua people in the Andes and as a seminary professor at the Ecuadorian Baptist Theological Seminary. He also served as Rector and professor of the Baptist seminary as a missionary with Global Outreach International. Dr. Sills is the author of The Missionary Call , Reaching and Teaching, and two books on the Highland Quichua indigenous people published in Spanish by Editoral Abya Yala, Quichuas de la Sierra: Descubriendo un modelo de Pastoral adiestramiento pastoral culturalmente apropiado and Capacitation en la Cultura Quichua and Introduccion a la Misiologia.  Among his professional memberships are the Evangelical Missiological Society, the American Society of Missiology, and the Association of Professors of Mission.