Now if from such works any man chooses to demonstrate to us the character of the Cynic philosophy, and to blaspheme the gods and bark at all men, as I said when I began, let him go, let him depart to the uttermost parts of the earth whithersoever he pleases. But if he do as the god enjoined on Diogenes, and first “give a new stamp to the common currency,” then devote himself to the advice uttered earlier by the god, the precept “Know Thyself,” which Diogenes and Crates evidently followed in their actual practice, then I say that this is wholly worthy of one who desires to be a leader and a philosopher. For surely we know what the god meant? He enjoined on Diogenes to despise the opinion of the crowd and to give a new stamp, not to truth, but to the common currency. Now to which of these categories shall we assign self-knowledge? Can we call it common currency? Shall we not rather say that it is the very summary of truth, and by the injunction “Know Thyself” we are told the way in which we must “give a new stamp to the common currency”? For just as one who pays no regard whatever to conventional opinions but goes straight for the truth will not decide his own conduct by those opinions but by actual facts, so I think he who knows himself will know accurately, not the opinion of others about him, but what he is in reality. It follows then, does it not? that the Pythian god speaks the truth, and moreover that Diogenes was clearly convinced of this since he obeyed the god and so became, instead of an exile, I will not say greater than the King of Persia, but according to the tradition handed down actually an object of envy to the man who had broken the power of Persia and was rivalling the exploits of Heracles and ambitious to surpass Achilles. Then let us judge of the attitude of Diogenes towards gods and men,  not from the discourses of Oenomaus or the tragedies of Philiscus - who by ascribing their authorship to Diogenes grossly slandered that sacred personage - but let us, I say, judge him by his deeds.
Why in the name of Zeus did he go to Olympia? To see the athletes compete? Nay, could he not have seen those very athletes without trouble both at the Isthmian games and the Panathenaic festival? Then was it because he wished to meet there the most distinguished Greeks? But did they not go to the Isthmus too? So you cannot discover any other motive than that of doing honour to the god. He was not, you say, awestruck by a thunderstorm. Ye gods, I too have witnessed such signs from Zeus over and over again, without being awestruck! Yet for all that I feel awe of the gods, I love, I revere, I venerate them, and in short have precisely the same feelings towards them as one would have towards kind masters or teachers or fathers or guardians or any beings of that sort. That is the very reason why I could hardly sit still the other day and listen to your speech. However, I have spoken thus as I was somehow or other impelled to speak, though perhaps it would have been better to say nothing at all.
To return to Diogenes: he was poor and lacked means, yet he travelled to Olympia, though he bade Alexander come to him, if we are to believe Dio. So convinced was he that it was his duty to visit the temples of the gods, but that it was the duty of the most royal monarch of that day to come to him for an interview. And was not that royal advice which he wrote to Archidamus? Nay, not only in words but in deeds also did Diogenes show his reverence for the gods. For he preferred to live in Athens, but when the divine command had sent him away to Corinth, even after he had been set free by the man who had bought him, he did not think he ought to leave that city.  For he believed that the gods took care of him, and that he had been sent to Corinth, not at random or by some accident, but by the gods themselves for some purpose. He saw that Corinth was more luxurious than Athens, and stood in need of a more severe and courageous reformer.
To give you another instance: Are there not extant many charming poems by Crates also which are proofs of his piety and veneration for the gods? I will repeat them to you if you have not had time to learn this from the poems themselves: “Ye Muses of Pieria, glorious children of Memory and Olympian Zeus, grant me this prayer! Give me food for my belly from day to day, but give it without slavery which makes life miserable indeed. . . . . Make me useful rather than agreeable to my friends. Treasure and the fame thereof I desire not to amass; nor do I crave the wealth of the beetle and the substance of the ant. But justice I desire to attain, and to collect riches that are easily carried, easily acquired, precious for virtue. If I attain these things I will worship Hermes and the holy Muses, not with costly and luxurious offerings, but with pious and virtuous actions.”
You see that, far from blaspheming the gods as you do, he adored and prayed to them? For what number of hecatombs are worth as much as Piety, whom the inspired Euripides celebrated appropriately in the verses “Piety, queen of the gods. Piety”? Or are you not aware that all offerings whether great or small that are brought to the gods with piety have equal value, whereas without piety, I will not say hecatombs, but, by the gods, even the Olympian sacrifice of a thousand oxen  is merely empty expenditure and nothing else? This I believe Crates recognised, and so with that piety which was his only possession he himself used to honour the gods with praises, and moreover taught others not to honour expensive offerings more than piety in the sacred ceremonies. This then was the attitude of both those Cynics towards the gods but they did not crowd audiences together to hear them, nor did they entertain their friends with similes and myths, like the wise men of today. For as Euripides well says, “Simple and unadorned is the language of truth.” Only the liar and the dishonest man, he says, have any use for a mysterious and allusive style. Now what was the manner of their intercourse with men? Deeds with them came before words, and if they honoured poverty they themselves seem first to have scorned inherited wealth; if they cultivated modesty, they themselves first practised plain living in every respect; if they tried to expel from the lives of other men the element of theatrical display and arrogance, they themselves first set the example by living in the open market places and the temple precincts, and they opposed luxury by their own practice before they did so in words; nor did they shout aloud but proved by their actions that a man may rule as the equal of Zeus if he needs nothing or very little and so is not hampered by his body; and they reproved sinners during the lifetime of those who had offended but did not speak ill of the dead; for when men are dead even their enemies, at least the more moderate, make peace with the departed. But the genuine Cynic has no enemy, even though men strike his feeble body or drag his name in the mire, or slander and speak ill of him, because enmity is felt only towards an opponent, but that which is above personal rivalry is usually loved and respected.  But if anyone is hostile to a Cynic, as indeed many are even to the gods, he is not that Cynic's enemy, since he cannot injure him; rather he inflicts on himself the most terrible punishment of all, namely ignorance of one who is nobler than himself; and so he is deserted and bereft of the other's protection.
To the Cynic Heracleios (362) by Julian, translated by Emily Wilmer Cave Wright