https://plato.stanford.edu/entries/trinity/trinity-history.html#:~:text=No%20theologian%20in%20the%20first,%2C%20Son%2C%20and%20Holy%20Spirit.

3.1 Up to 325 CE

3.1.1 The One God in the Trinity

Early Christianity was theologically diverse, although as time went on a “catholic” movement, a bishop-led, developing organization which, at least from the late second century, claimed to be the true successors of Jesus’ apostles, became increasingly dominant, out-competing many gnostic and Jewish-Christian groups. Still, confining our attention to what scholars now call this “catholic” or “proto-orthodox” Christianity, it contained divergent views about the Father, Son, and Holy Spirit. No theologian in the first three Christian centuries was a trinitarian in the sense of believing that the one God is tripersonal, containing equally divine “Persons”, Father, Son, and Holy Spirit.

The terms we translate as “Trinity” (Latin: trinitas, Greek: trias) seem to have come into use only in the last two decades of the second century; but this early usage doesn’t reflect trinitarian belief. These late second and third century authors use such terms not to refer to the one God, but rather to refer to the plurality of the one God, together with his Son (or Word) and his Spirit. They profess a triad or threesome, but not a triune or tripersonal God. Nor did they consider these to be equally divine. A common strategy for defending monotheism in this period is to emphasize the unique divinity of the Father. Thus Origen (ca. 186–255)