Justin Martyr, also Justin of Caesarea, or Justin the Philosopher (ca. 100–165). Born at Flavia Neapolis, the present day Nablus, about A.D. 100, converted to Christianity about A.D. 130, taught and defended the Christian religion in Asia Minor and at Rome, where he suffered martyrdom about the year 165. Two "Apologies" bearing his name and his "Dialogue with the Jew Tryphon" have come down to us. Irenaeus tells us that Justin Martyr wrote a work against Marcion, which is now lost.

I have tried to learn about every system, but I have accepted the true doctrines of the Christians, though these are not approved by those who are held fast by error.

- Justin Martyr

Justin was educated as a philosopher before he was converted to Christianity. As such his writings try to connect the truths he sees in philosophy with the truths relieved in the Jewish prophetic tradition. He tells the story of his conversion: One day while walking along a shore and reading Plato. He is approached by an old man who says "I see you are a philosopher and a lover of knowledge, have you ever heard of the Jewish prophets who have spoken of a man that was born not far from where you were born and this is the true wisdom." Justin is intrigued and starts reading the Jewish prophets. He has heard of the Christians, indeed he has seen them martyred and notices that they do not scream curses but they huddle together attending to one another and died nobly. This further intrigues him and he enrolls to be taught and is subsequently baptized. Even after his conversion he continued to wear the robes of a philosopher. Christianity was not a public religion in his day, but Justin is very public about it. His education allows him to author his apologies the first of which is addressed to the Emperor.

This apology, addressed to Emperor Antoninus, who ruled from 138-161 is dated internally from the statement in chapter 6 that "Christ was born one hundred and fifty years ago under Cyrenius." Since Quirinius entered office in the year 6 A.D. according to Josephus, the apology may be dated to the year 156 A.D. This is his most well-known text. In it he passionately defends the morality of the Christian life, and provides various ethical and philosophical arguments to convince the Roman emperor, Antoninus, to abandon the persecution of the Church. Further, he also indicates, as St. Augustine would later, regarding the "true religion" that predated Christianity, that the "seeds of Christianity" (manifestations of the Logos acting in history) actually predated Christ's incarnation. This notion allows him to claim many historical Greek philosophers (including Socrates and Plato), in whose works he was well studied, as unknowing Christians.

Justin was martyred, along with some of his students; Chariton, Charites, Pæon and Liberianus. See the Martyrdom of Justin.

Eusebius of Caesarea deals with him at some length, and names the following works:

First Apology - addressed to Emperor Antoninus Pius, his sons, and the Roman Senate;
Second Apology - addressed to the Roman Senate;
Dialogue with Trypho
Discourse to the Greeks - a discussion with Greek philosophers on the character of their gods;
Hortatory Address to the Greeks;
On the Sovereignty of God - a syncretic text in which he makes use of pagan authorities as well as Christian;
The Psalmist - a lost work;
and On the Soul.

 

https://www.newadvent.org/fathers/0133.htm 

https://en.wikipedia.org/wiki/Justin_Martyr

http://www.earlychristianwritings.com/justin.html

https://www.newworldencyclopedia.org/entry/Justin_Martyr 11/29/21

https://www.crossroadsinitiative.com/media/videos/the-contribution-of-justin-martyr-video/ 11/29/21