"And so the road they followed was a winding ascent, an ascent surmounted by a beacon. The ascent refers to works and the beacon to faith, so that we can see the great difficulty and laborious effort involved in both faith and works. Many are the temptations we shall meet and many the obstacles to faith that lie in store for us in our desire to pursue the things of God."
Origen of Alexandria (AD 185-253), Hom. in Exodo 5, 3-4: Edit. Maurist. 2, 145-146.
Origen became head of the catechetical school of Alexandria and devoted his life to the study of scripture. When he became a Christian, he sold all his many books, a decision he later regretted (and which still makes me wince). Over the years, he was plagued by rumors that he may have castrated himself out of misguided zeal for Christ's command in Matthew 5:27-30. Self-mutilation was condemned as a heresy in the early Church, so the enormity of this rumor was a constant thorn in his side. Having been persecuted and exiled numerous times, in many cities, he died at the age of sixty nine in Tyr.
After his death, he was condemned for positively teaching (Platonic) heresy, including among other things his subordinationist views about Christ and his doctrine of apokastasis, according to which all beings -- even the Devil -- will be saved and reconciled to God. Despite these controversies and blemishes, Origen's contribution to biblical exegesis is immense and the majority of his writings are an immense treasure for the Church. I am moved by how Origen's tremendous spiritual zeal for Christ drove his intellectual work.