Patristics (early church Fathers) are not a valid hermeneutic to interpret the content of the NT. However, we do know that contained in the vast quantity of pre-Nicaea literature, the early fathers did hold consistently and decisively (within the limitations of their cultural vernacular and doctrinal expressions), the Christological essentials of the apostolic teaching particularly regarding monotheism and Jesus Christ as God incarnate within a trinitarian concept. We also we find significant theological descriptions as to Son’s atoning cross work.
For example, note a few of many remarkable theological terms and phrases that the apostolic Father, Ignatius bishop of Antioch (c. A.D. 107) applies to Christ in his “genuine” letters:
Ἀγέννητος (agennētos, “There is only one physician, who is both flesh and spirit, born and unborn [ἀγέννητος], God in man, true life,” Ephesians 7:2). Ἀγέννητος was technical term meaning unbegotten, unborn, unoriginated (Kelly, BDAG, Liddell et al.) distinguishing God (here, the incarnate God) from creatures.
Ὁ γὰρ θεὸς ἡμῶν Ἰησοῦς Χριστός (Ho gar theos hēmōn Iēsous Christos, “For our God, Jesus Christ,” Romans 3.3). Ignatius frequently referred to Christ as θεὸς (theos, “the/our God”) or similar phrases, and does so in distinction to the Father (e.g., Rom. prologue; Eph. 18; Polycarp 8.3 et al.). Further, contra the erroneous claims of Oneness advocates, there is no place in the Greek of Ignatius’s genuine letters where grammatically he says Jesus is the Father; rather Ignatius always differentiates Jesus from the Father—as two distinct divine persons.
Ἰησοῦ Χριστοῦ, ὃς πρὸ αἰώνων παρὰ πατρὶ ἦν (Iēsou Christou, hos pro aiōnōn para patri ēn, “Jesus Christ, who before the ages was with the Father,” Magnesians 6.1). In affirming the preexistence of the person of the Son, in distinction to the Father, note the syntactical similarity of Magnesians 6:1 and John 17:5.
First both John and Ignatius use the prepositional phrase, παρὰ (para, “with, alongside of”) + the dative case indicating a clear distinction of persons (John 17:5- παρὰ σεαυτῷ, παρὰ σοί, “together with Yourself,” “with You”; Magnesians 6:1- παρὰ πατρὶ, “with [the] Father”).
Second, both passages use the preposition πρὸ (“before”) indicting the actual preexistence of the person of the Son (John 17:5- πρὸ τοῦ τὸν κόσμον εἴναι, “before the world was”; Magnesians 6:1- πρὸ αἰώνων, “before [the] ages”).
ἐν αἵματι θεοῦ (en haimati theou, “by the blood of God”; “being imitators of God, and having your hearts kindled in the blood of God, you have perfectly fulfilled your congenial work,” Ephesians 1.1). This most interesting phrase resembles Paul’s statement in Acts 20:28: “the church of God, which He purchased with His own blood.”
Although the phrase in Acts 20:28 (διὰ τοῦ αἵματος τοῦ ἰδίου, lit., “with the blood of His own”) could be translated as “with the blood of His own Son” (possessive genitive, NET, CEV), Ignatius’s meaning is unambiguous (pre-Nestorian). In his Intro to the same letter (Ephesians), he refers to Jesus Christ as τοῦ θεοῦ ἡμῶν (“our God”). Thus, for Ignatius, the “by the blood of God” would be the blood of the incarnate God, Jesus Christ.
Many more statements of Ignatius could be cited. Although Ignatius, along with other important apostolic Fathers (and subsequent ones), lacked modern articulation of doctrinal words and phrases, Ignatius did indeed clearly hold to an essential Christology, where salvation is through the blood of incarnate God the Son, preexisting before the ages, παρὰ πατρὶ (“with the Father”).