"Today the concept of truth is viewed with suspicion, because truth is identified with violence. Over history there have, unfortunately, been episodes when people sought to defend the truth with violence. But they are two contrasting realities. Truth cannot be imposed with means other than itself! Truth can only come with its own light. Yet, we need truth. ... Without truth we are blind in the world, we have no path to follow. The great gift of Christ was that He enabled us to see the face of God".Pope Benedict xvi, February 24th, 2012
The Church is ecumenical, catholic, God-human, ageless, and it is therefore a blasphemy—an unpardonable blasphemy against Christ and against the Holy Ghost—to turn the Church into a national institution, to narrow her down to petty, transient, time-bound aspirations and ways of doing things. Her purpose is beyond nationality, ecumenical, all-embracing: to unite all men in Christ, all without exception to nation or race or social strata. - St Justin Popovitch
Justin's conversion to Christianity is thought to have happened at the city of Ephesus, around A.D. 130, when our inquisitive young Samaritan was roughly thirty years of age. And though he was undoubtedly given a warm reception into the Christian congregation there in Asia—that venerable church founded by John, written to by Ignatius from the house of Polycarp—Justin, to tell the truth, may have raised a few eyebrows by his conduct as a new believer. For the fact is that he continued to frequent his old haunts. He kept all his old friendships and ran with the same unregenerate crowd he had associated with as a heathen. In short, Justin of Neapolis became known, much like his Lord before him, as "the friend of publicans and sinners"—only in Justin's case, the publicans and sinners were not prostitutes or winebibbers, but mystic Pythagorean mathematicians and long-faced logicians studiously following Xenophon and Parmenides. In other words, Justin became an apologist—a defender of the faith, a philosophical evangelist—and from the day of his redemption he seems to have been possessed by one burning desire: to see his own people, his brother philosophers, come to the knowledge of the truth.
The Dialogue with Trypho, which took place at Ephesus during this period,  gives us a window into Justin's methods. As it opens, we find him, wearing his pallium, walking among the colonnades of a great temple (possibly the same great temple of Diana where earlier Paul had raised the ire of the silversmiths [Acts 19]). Such places were where the philosophers of the day plied their trade, and little groups of them could always be found arguing, from sun up to sun down, on the steps of every pagan shrine in the Empire. On this particular day, Justin drew the attention of Trypho, the Hellenized rabbi, famous as one of the most learned Jews in the East. Yet it might just as well have been the representative of any of a hundred different world views who chose to debate him that day, for they all met here on equal terms, all contending (though they little knew it at the time) for the intellectual fate of Europe and the world.
In the case of Trypho, the conversation turns quickly to Old Testament prophecy and its alleged fulfillment in Jesus of Nazareth. But even with pagan opponents Justin was known to declare his Christianity boldly—and this in spite of the popular mania against the Faith that swirled around him like a tempest. While this is certainly brave, it is not quite reckless. Justin knows, and is consciously depending upon, an unwritten code of honor current among Greek philosophers. Socrates' great motto had been to "follow the argument wherever it leads"—and, as a result, his successors held the keeping of an open mind to be among the highest of virtues. They prided themselves upon the fact that just about any viewpoint could gain a respectful hearing among them—at least until they felt that it had been conclusively disproved. Therefore, to surrender their old comrade to the authorities solely because he had altered his opinions would have been seen as a serious violation of their liberal traditions.
And so Justin walks a tightrope. His beliefs are outlawed and he knows that there is not another public platform in the Empire open to his message. Yet he also knows that One false step will send him to the lions. His chosen strategy, then, is precarious in the extreme, and strangely poignant. Justin will count, prayerfully and trustingly, on the intellectual integrity of his old friends. He will speak, as only a man in his unique position could, to the one group of Roman citizens on earth who are committed not to turn him in for treason.
What is his approach? In the true spirit of discipleship, Justin resolves to walk in the footsteps of his own spiritual father—a certain nameless Old Man, the gentle but tough-minded Christian Socrates who once beat him at his own game. Justin will practice logic with the logicians; he will use philosophy on the philosophers. To the Platonists, he will remain a Platonist; to the Stoics, he will talk Stoicism—and talk it better than they can, and more ruthlessly. He will become all things to all men, that he might by all means save some.
The best example of Justin's apologetic, perhaps, comes in his answer to their most serious and common objection. The single greatest stumbling block for pagan academics, it seems, was Christianity's exclusivity—its claim to be the one true religion, the one sure way to God, established by God. Were the Christians really saying that the whole world had been stumbling hopelessly in the dark until a mere one hundred years ago? Was Justin now asking his friends to deny all the priceless insights they had learned together by their study of philosophy? Would a man not have to commit something like intellectual suicide to do that? And had Justin himself managed such a feat? Did their respected colleague now consider himself a mere Christian sectary—just another mystery cultist, making, as the skies blackened over Rome, just one more religious leap in the dark?
Justin answered—and in his answer Jerusalem and Athens speak together for the first time; the new City of God, set on a hill forever: "[Yes,] I confess that I both pray and with all my strength strive to be found a Christian; not because the teachings of Plato are different from those of Christ, but because they are not in every respect equal." Certainly Plato spoke the truth, responds Justin. So did all the poets and philosophers and historians! For each person spoke well, according to the part present in him of the divine logos, the Sower.... We [Christians, on the other hand,] worship and love the Logos, who is from the unbegotten and ineffable God, since He became man for our sakes; so that, by becoming a partaker of our sufferings, He might also bring us healing. All the writers were able to see realities darkly [cf. I Cor 13: 12], through the presence in them of an implanted seed of logos. For the seed and imitation of something, imparted according to capacity, is one thing, and another is the thing itself. 
What we have, then, appears to be greater than all human teaching, because the whole rational principle became Christ who appeared for our sake, body, and reason, and soul. 
Therefore, whatever things were rightly said among all people are the property of us Christians.  What an astonishing set of words! The whole glorious history of Christian thought is prefigured here, from Augustine to Aquinas to C. S. Lewis! And—more to our own point—what a magnificent obstacle God has raised up in the path of Marcus Aurelius: iron to sharpen iron, mind to answer mind, fashioned by the Spirit to save the soul of an emperor!
 Though the debate itself is believed to have taken place just after the Bar Cocheba uprising in A.D. 132, the final written form of the Dialogue dates from later—probably about 160.
 Justin Martyr, First Apology, chap. 13, trans. Leslie William Barnard, in St. Justin Martyr, The First and Second Apologies, ACW, vol. 56 (New York: Paulist Press, 1997), pp. 83-84.