Christ Jesus said that signs would follow believers—those who understood his lifework and its message. He promised, "They shall speak with new tongues." Mark 16:17.
Throughout Christendom, conceptions of the fulfillment of this promise have ranged from the practice known as glossolalia to a fixed belief that the promised signs were meant only "to assist the diffusion of the gospel at the very first." J. R. Dummelow, The One-Volume Bible Commentary (New York: Macmillan Publishing Co., 1978), p. 733.
A renaissance of the genuine signs Jesus foretold came with Mrs. Eddy's discovery of Christian Science. Science brings newness to both aspects of the Greek word translated tongue, which is defined literally as "a member of the body, the organ of speech" and figuratively as "the language used by a particular people in distinction from that of other nations." J. H. Thayer, A Greek-English Lexicon of the New Testament, 4th ed. (New York: Charles Scribner's Sons, 1901), p. 118.