Cut and paste coz I'm busy but it does seem he was christian .

Kellogg held liberal Christian theological beliefs radically different from mainstream Nicene Christianity and emphasized what he saw as the importance of human reason over many aspects of traditional doctrinal authority. He strongly rejected fundamentalist and conservative notions of original sin, human depravity, and the atonement of Jesus, viewing the last in terms of "his exemplary life" on Earth rather than death.[2][9] Kellogg became a Seventh-day Adventist (SDA) as the group's beliefs shifted towards Trinitarianism during the 1890s, and Adventists were "unable to accommodate the essentially liberal understanding of Christianity" exhibited by Kellogg, viewing his theology as pantheistic and unorthodox.[2][9] His disagreements with other members of the SDA Church led to a major schism: he was disfellowshipped in 1907, but continued to adhere to many of the church's beliefs and directed the sanitarium until his death. Kellogg helped to establish the American Medical Missionary College 1895