Born in Palestine, Justin (c. 100-167) spent his early years immersed in philosophy. Though a professional philosopher (Platonist), he was impressed with the courage of Christians facing death for their faith. He converted to Christ in A.D. 130 through the witness of an old Christian man who spoke to him of the true “philosophy”. This truth was revealed trough biblical prophets foretelling events to come and was confirmed by miracles. Justin's heart was stirred and thereafter he spent his days seeking to introduce others to Christ. Faithfulness to his confession of Christ ultimately led to his beheading at Rome-hence the name Justin Martyr.
Justin would go on to write several apologetic treatises, including two addressed to the Roman emperors Antoniinus Pius and Marcus Aurelius. In these works Justin, sought to prove the injustice of the persecution of Christians. He defended Christians from false charges such as atheism. Their refusal to bow before pagan idols and worship the emperor stemmed from their worship of the true God, who is invisible as Creator of all things. Demons are the true source of the hatred instigated toward Christians. Traces of truth that may be discovered in pagan philosophers writing before Christ were borrowed from the Hebrew Scriptures or else are due to the pre-incarnate Christ as Logos (the rational power guiding the universe) enlightening them. The biblical prophets accurately prophesied the coming of this Christ as the central figure of history.
Extracted from the Apologetics Study Bible.