Origen

Origen (c.e. 185-254) was a scholar and early Christian theologian who was born and spent the first half of his career in Alexandria. He was a prolific writer in multiple branches of theology, including textual criticism, biblical exegesis and hermeneutics, philosophical theology, preaching, and spirituality written in Greek.

Origen produced the Hexapla, the first critical edition of the Hebrew Bible, which contained the original Hebrew text as well as four different Greek translations of it, and one Greek transliteration of the Hebrew, all written in columns, side by side.

Hexapla was to provide a secure basis for debate with rabbis to whom the Hebrew alone was authoritative. At Alexandria he wrote Miscellanies (Stromateis), On the Resurrection (Peri anastaseos), and On First Principles (De principiis).

He wrote De principiis which was an ordered statement of Christian doctrine. He believed every Christian is committed to the rule of faith laid down by the Apostles and the God of both Old and New Testaments.

Origen believed in the Creator and the Lord and the Holy Spirit but there was no teaching of the Trinity which would be pushed by some bishop of the First Nicene Council. Origen said these three were "homoousios" which does not mean they were "one in the same being" but actually meant "of the same kind of stuff as". It was a common word used in Greek and also by the Gnosticism

The Latin word Trinitas, would be coined by Tertullian.

The De principiis actually diverged from later standards of orthodoxy.

Origen’s great vindicated Christianity concerning pagan attack in the Contra Celsum, written at Ambrose’s request. The answers to the 2nd-century anti-Christian philosopher Celsus contained in the fragments of the Philocalia and in the Alēthēs logos which has been called “The True Doctrine” or “True Discourse”.

Around 233 he wrote "On Prayer" which expounds the Lord’s Prayer and discusses some of the philosophical problems of petition for what you want.

Origen suggested because of accounts from others that the Zechariah mentioned in Matthew 23:35 who was killed between the temple and the altar may be the father of John the Baptist. (Reimund Bieringer, The Corinthian Correspondence, page 497, footnote 20). In Fact, he was emphatic that Zechariah was killed by the scribes and Pharisees and not by Herod. Several Byzantine authors do not connect the prophet of 2 Chronicles 24 the Zachariah of Matthew 23.35