Mormon, in prophesying about the coming forth of the words of the Book of Mormon, declares the doctrine that the Father and the Son are separate beings yet both are Gods:
And behold, they shall go unto the unbelieving of the Jews; and for this intent shall they go--that they may be persuaded that Jesus is the Christ, the Son of the living God; that the Father may bring about, through his most Beloved, his great and eternal purpose, in restoring the Jews, or all the house of Israel, to the land of their inheritance, which the Lord their God hath given them, unto the fulfilling of his covenant. (Mormon 5:14)
According the Richard Hopkins, the earliest apologetic writing of which a clearly genuine copy is available today is the Epistle to Diognetus, written in about A.D. 130. The author and addressee of this letter are completely unknown. Internal evidence suggests that it was written by someone who lived at the beginning of the second century. He describes himself as follows: "having been a disciple of the Apostles, I am become a teacher of the Gentiles." If this is true, the writer would be properly included among the Apostolic Fathers. . . . The Epistle contains statements that are completely consistent with biblical Mormonism. The author repeatedly refers to the Father and the Son as entirely separate individuals and at one point describes their relationship as follows: "As a king sends his son, who is also a king, so sent He Him; as God." This understanding of the relationship between the Father and the Son--as of a King and His Prince--is a clear and accurate expression of biblical theology. It recognizes the complete separation of the individual who is King from the individual who is Prince, while it explains the filial relationship between the two that allows the Son to be called God without violating the authority of His Father, the King. [Richard R. Hopkins, How Greek Philosophy Corrupted the Christian Concept of God, p. 126]