The oldest surviving sermon of the Christian church after the New Testament opened with the words: “Brethren, we ought so to think of Jesus Christ as of God, as the judge of living and dead. And we ought not to belittle our salvation; for when we belittle him, we expect also to receive little.”
The oldest surviving account of the death of a Christian martyr contained the declaration: “It will be impossible for us to forsake Christ . . . or to worship any other. For him, being the Son of God, we adore, but the martyrs . . . we cherish.”
The oldest surviving pagan report about the church described Christians as gathering before sunrise and “singing a hymn to Christ as to [a] god.”
The oldest surviving liturgical prayer of the church was a prayer addressed to Christ: “Our Lord, come!”
Clearly it was the message of what the church believed and taught that “God” was an appropriate name for Jesus Christ.
—Jaroslav Pelikan, The Christian Tradition: A History of the Development of Doctrine, Vol. 1: The Emergence of the Catholic Tradition (100-600) (Chicago: University of Chicago Press, 1971), p. 173; emphasis added.