|Origen: neither heretic nor saint|
Leonidas was a professor of rhetoric in Alexandria who was imprisoned and beheaded in AD 202 by Laertus, the governor of Egypt. Leonidas was killed for his Christianity, so all his property was confiscated. His wife and seven sons were impoverished until the family was adopted by a wealthy Christian woman.
One son, Origen, was perhaps the most brilliant Christian thinker of the third century. Well, he's got some stiff competition, but top five, easy. He is considered the father of the homily, and wrote thousands of pages of commentary on religious texts.
He survived the persecutions of Maximian, but was imprisoned and tortured during the persecutions of Decius.
He'd be a shoo-in for sainthood, right? Sure, except that his speculative ideas were later branded heresy when the mania for definitive orthodoxy was in full bloom. They couldn't do anything to Origen himself -- Decius had seen to that -- but they could identify forbidden ideas as Origenism and thereby block any possible sainthood.
The picture above, by the way, was taken from the Animal Liberation Front website, which quotes him offering an explanation of why we eat meat.