I have read and studied Origen's writings for many years. He was the leader of the "seminary" in Alexandria. A lay person who taught Priests, and later Bishops - though he was chastised for this. He moved to Caesarea to start a "seminary" there. And he taught and influenced some of the great Church Fathers, and he is quoted by Pope Benedict in his own work.
He was the first systematic theologian and taught in the mid 3rd. cent. He wrote many commentaries which are wonderful understandings of God's intervention in the lives of believers. He explained justification.
He had many fans, including St. Augustine.
He also wrote several books that speculated on the origin of man, and the purpose of man, and where spirits came from and went to - but these were just ideas for others to ponder - he didn't say they were the truth.
Some of his followers took his speculative ideas and ran with them and taught things that he would never have approved. What they taught was termed Origenism by the catholic Bishops, and their ideas - especially about the pre-existence of souls (LDS are you hearing this) which Origen had speculated on, were anathema. His suggestion that everyone was going to be redeemed, was an idea of his own. Strangely on May 22 this year Pope Francis suggested essentially the same thing
"The Lord has redeemed all of us, all of us, with the Blood of Christ: all of us, not just Catholics. Everyone! ‘Father, the atheists?’ Even the atheists. Everyone!".. Pope Francis 5/22/2013 Huffington Post report.
But remember that in AD 250 when he taught, there was no systematic theology before him. His book De Pricipia was the source of these speculations.
But this was just one book out of the hundreds he wrote. His commentaries are wonderful to read.
Iranaeus of AD 150 was the only other person to define what was Christianity. He wrote his six volume treatise on the various misconception of Jesus being taught by many Bishops. Early theologians (he was also a Bishop,) had a different opinion of the Gospel message than we have today. Though he was the first church historian, he was not familiar with the details of the death of Jesus, and thought he was 48 years old when he died.
Origen focussed only on unbuttoning the secrets of the gospels, and not church politics. His biographers estimate he had written more than 6000 manuscripts about Jesus's teaching. Most are lost. A few of the original Greek mss. exist, and there are many Latin translation by Rufinus.
There is absolutely no point in reading summaries in the encyclopedia about him. Most people haven't spent enough time to even begin to understood his work. He was a mystic who taught the three different ways of understanding scripture. if you want to understand Jesus's parables, this is the man to consult.
Don't believe what is said about him, by people who have never read him (which is where your original comment came from - someone who did not know his work.)
Fathers from the 3rd. cent. considered Origen to be a genius, and he is revered by some Catholic and Greek leaders today. One of the most beloved books used in the Orthodox church today is the Philokalia, and Origen made a major contribution to the books. I own Vol 1, and IV.
If you like John Le Carre's writing with its mysteries and convoluted plots, you should enjoy Origen - they are just about the same reading level.