I would like to add that there is one Apostle, Disciple or Jesus stating and teaching a three person doctrine, a name of Trinity or saying God is a plurality of beings, so the 1st century is silent on this idea totally, one must come with a preset idea of a triune godhead and then try and fit a system belief to that and not get it from any set of p***ages whether by themselves or together.
Second century Post Apostolic writings are void of such and has men who are using a two god idea (The Holy Ghost doctrine not yet formulated for many as a third).
The 2nd century writer clostest would be Thophilus late in the second century and using a term Trias or Triad a term ***ociated with the old Triple god view of pagans.
Third century we see Tertullian speak in Against Praxeas chapter 3 that God is a economia, which is a three in one, and yet he tells on himself and his kind that the "MAJORITY" OF BELIEVERS in his day call him a believer in two and three gods.
Add to that, that it took till the 4th century and Nicea to develop and formulate this doctrine and finally able to pronounce it in a way to defeat Arius and avoid deally with Monarchians, who had been up till then the Majority, and who lost control of the Bishopric of Rome right around 222 a.d. when Callixtus was stoned to death by a mob and was the last of a long line of Monarchians dating back to Peter and maybe Paul there.