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 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. Among his professional memberships are the Evangelical Missiological Society, the American Society of Missiology, and the Association of Professors of Mission.