Ante-Nicene Fathers, Vol I:
IGNATIUS: Chapter II.—Unity of the three...

Chapter II.—Unity of the three divine persons.

There is then one God and Father, and not two or three; One who is; and there is no other besides Him, the only true [God]. For “the Lord thy God,” saith [the Scripture], “is one Lord.” 1305 And again, “Hath not one God created us? Have we not all one Father? 1306 And there is also one Son, God the Word. For “the only-begotten Son,” saith [the Scripture], “who is in the bosom of the Father.” 1307 And again, “One Lord Jesus Christ.” 1308 And in another place, “What is His name, or what His Son’s name, that we may know?” 1309 And there is also one Paraclete. 1310 For “there is also,” saith [the Scripture], “one Spirit,” 1311 since “we have been called in one hope of our calling.” 1312 And again, “We have drunk of one Spirit,” 1313 with what follows. And it is manifest that all these gifts [possessed by believers] “worketh one and the self-same Spirit.” 1314 There are not then either three Fathers, 1315 or three Sons, or three Paracletes, but one Father, and one Son, and one Paraclete. Wherefore also the Lord, when He sent forth the apostles to make disciples of all nations, commanded them to “baptize in the name of the Father, and of the Son, and of the Holy Ghost,” 1316 not unto one [person] having three names, nor into three [persons] who became incarnate, but into three possessed of equal honour.

Footnotes

Deut. vi. 4; Mark xii. 29.

Mal. ii. 10.

John i. 18.

1 Cor. viii. 6.

Prov. xxx. 4.

i.e., “Advocate” or “Comforter;” comp. John xiv. 16.

Eph. iv. 4.

1 Cor. xii. 13.

Eph. iv. 4.

1 Cor. xii. 11.

Comp. Athanasian Creed.

Matt. xxviii. 19.