Origen (185-254) Is referred to by many as an heterodox. His teaching was judged heretical by the Fifth Ecumenical Council in 553. Although today he is listed as one of the respected Church Fathers. He is credited with one of the first intellectual attempts to describe Christianity.

Origen's most famous work On First Principals rebutted Gnosticism at length. Origen was well educated and quite familiar in the Greek philosophers and so well qualified for this task. It is common these days to consider Gnosticism a melding of the Christian message with pagan philosophy.

According to Epiphanius (Haer., lxiv.63) Origen wrote about 6,000 works. A list was given by Eusebius in his lost life of Pamphilus (Hist. eccl., VI., xxxii. 3; Eng. transl., NPNF, 2 ser., i. 277), which was apparently known to Jerome (Epist. ad Paulam, NPNF, vi. 46). His writings fall into four classes: text criticism; exegesis; systematic, practical, and apologetic theology; and letters; besides certain spurious works.

According to the Catholic Encyclopedia the heresy that bears the name Origenism is understood not so much as Origen's theology and the body of his teachings, as it is a certain number of doctrines, rightly or wrongly attributed to him, and which by their novelty or their danger called forth at an early period a refutation from orthodox writers. They are chiefly:

  • Allegorism in the interpretation of Scripture
  • Subordination of the Divine Persons
  • The theory of successive trials and a final restoration.

His work in text criticism includes his Hexapla, a parallel Greek Old Testament that compared 5 translations of the Hebrew scriptures with the Hebrew. This was an attempt to find a standard Greek text of the Old Testament.

http://en.wikipedia.org/wiki/Origen 

http://www.iep.utm.edu/o/origen.htm