Justin Martyr (ca. 100–ca. 165) was born in Flavia Neapolis, which maps onto Nablus in modern Palestine. He slyly tells us he came of pagan, not Jewish, stock by specifying the configuration of his configurable (let the reader understand).
Justin first studied under a Stoic philosopher, until he realized his teacher had nothing to teach him about God. He then fell in with a Peripatetic, but realized the guy was a fraud when he got the bill (that, and he sat down a lot for a peripatetic). A Pythagorean refused to teach him about God until he first learned music, astronomy, and geometry (seems reasonable to me), and Justin wasn’t interested in those things (Philistine!). His last attempt to learn from the philosophers came in the form of a Platonist, who delighted Justin, for a time. Something was still lacking, though.
Around age 30, during a visit to Ephesus, Justin fell into a chance seaside discussion with an old Palestinian Christian (as one does), who averred that God could not be approached through the teachings of the philosophers, but must be revealed by the prophets. This kindled a love of Christ in Justin’s heart, and witnessing (or remembering witnessing) some Christians go fearlessly to their martyrdom—which, he reasoned, they could not do if they were living for sinful pleasure—sealed the deal. He was soon baptized, and began teaching and writing. He eventually ended up in Rome (all roads…), where he opened a school.
When the emperor Antoninus Pius cranked the persecution knob to 11, Justin wrote an apology (now called the First Apology to distinguish it from a different one) in defense of certain Christians who were condemned to die. In it, he argued that they were being slandered merely for calling themselves Christians (for values of “being slandered” equaling to “being condemned to death” and not “being insulted on Facebook”), and that people shouldn’t be killed unless they, like, broke a law or something. The emperor relented, and sent Justin to Asia Minor to call off the persecution there as well.
The First Apology (ca. 155) is an important source for our knowledge of Christian practice and belief in the mid-second century. Justin defends Christianity as a rational philosophy, equating Jesus with the Logos of the Greek philosophers, and reasoning that people before Christ who spoke with reason were in some sense Christian. Nevertheless their truth, he says, is only partial truth, whereas Christianity represents the fullness of truth. (No, he does not add, “So there!”)
He describes the Holy Eucharist as “the flesh and blood of that Jesus who was made flesh,” speaks of the “cup of wine mixed with water,” and tells how the blessed Food is distributed to the people by the deacons. He witnesses to the practice of fasting in preparation for baptism, and to Christian worship being on Sundays, as the day on which Christ rose from the dead. He refers to Gospels in the plural, and describes them as “memoirs of the apostles.”
After trouncing the Cynic philosopher (and sore loser) Crescens in debate for the umpteenth time, Justin was falsely accused (of what I could not discover) to the emperor (by this time Marcus Aurelius). He and six others were tortured and beheaded. His relics reside in the church of John the Baptist in Sacrofano, just a couple of miles north of Rome on the SP35b. He is, of course, the patron saint of philosophers.