Spiritual formation is a critical concern for any Christian religious educator. While Scripture provides a depiction of spiritual growth, we have often turned to the developmental theorists to better understand the ecology of spiritual formation. One neglected voice in this instance is the late Russian developmentalist Lev S. Vygotsky. His unique perspective on human cognitive development provides an alternative to traditional developmentalism, and additional insight into the ecology of spiritual formation. This article will endeavor to explain the role of developmental theories in understanding spiritual formation, the developmental theory of Vygotsky, and its implications for our understanding of spiritual formation and Christian religious education as a means of advancing it. (Contains 8 figures and 1 table.)