3. and this is eternal life] In this it is placed; prepared in this way. A Metonymy, as above 6:63, 11:25, 12:50, 14:6. Similar kind of speech – Romans 11:12.
that they may know you the one true God] This ἵνα is εἰδιϰὸν [specificative]. For it is described a manner of prepared eternal life, which such is that the glory of God the Father chiefly may be viewed. Γινὠσϰειν this will be understood πραϰτιϰῶς [active], that 1:10, that they may know, be embraced, cultivate, and may revere you the only God, excluding all them who had introduced the falsehoods of the nations*. Ignatius speaking to the Magnesians concerning Jesus: “who having been thrust to the multitude of gods has declared the one and only God his Father. “ In the Constitutions of Clement to the converts from the gentiles: "For you are translated from your former vain and tedious mode of life and have contemned the lifeless idols, and despised the demons, which are in darkness, and have run to the true light, and by it have known the one and only true God and Father, and so are owned to be heirs of His kingdom." See 1 Thessalonians 1:9
*Persuasio (nominative noun meaning persuasion) is used, but I could not figure out how to fit in the sentence.
Bible Study Tools translation of Ignatius to the Magnesians: “and to those who had fallen into the error of polytheism He made known the one and only true God, His Father.”