Armenius: Diligentia

This short doctrinal piece, transmitted under the name of an otherwise obscure Armenius, sets out the catholic faith in the Trinity. It confesses Father, Son and Holy Spirit as three coeternal and coequal persons of one substance and one God, and firmly rejects the charge that this amounts to belief in three gods: the distinction lies only in names and persons, while the one invisible and incomprehensible deity is wholly in each. The later part of the text explains a series of scriptural titles of Christ one by one, each with a brief reason: Way, Life, King, Priest after the order of Melchizedek, Arm, Right Hand, and Net, because he came into the world as into a sea and gathered his elect.

Little is known of the author or the date of composition, and the text is best read on its own terms as a compact creed and catechetical aid. Its list of the names of Christ with short explanations belongs to a widespread tradition of such lists in early Latin Christian writing, used to teach the faithful how to read the titles of Christ in Scripture. It is a useful example of the plain, formulaic Latin in which Trinitarian orthodoxy was taught.