From one man he made all the nations, that they should inhabit the whole earth; and he marked out their appointed times in history and the boundaries of their lands. God did this so that they would seek him and perhaps reach out for him and find him, though he is not far from any one of us. ‘For in him we live and move and have our being.’ [NIV]
The second time is in Titus, talking about the people of Crete and Titus's responsibilities with regard to them:
For there are many rebellious people, full of meaningless talk and deception, especially those of the circumcision group. They must be silenced, because they are disrupting whole households by teaching things they ought not to teach—and that for the sake of dishonest gain. One of Crete’s own prophets has said it: “Cretans are always liars, evil brutes, lazy gluttons.” This saying is true. [NIV]
Both of these quotations are from one source, the Cretica. It has not really survived, but we do have speculative stitching-togethers of bits and pieces of evidence by various scholars. (In what follows, as with the rest of the series, I am less interested in anything scholarly than in simply pointing out sources accessible online where anyone who wants to do so can make a start at looking at the matter more closely.)
It has been noted for a very long time that the Epistle to Titus is not the only source talking about Cretan liars, and one source in particular seems to be quite explicit about what the lie was that got everyone's dander up, Callimachus's Hymn to Jupiter:
The Cretans, prone to fasehood, vaunt in vain,
And impious! built thy tomb on Dicte's plain;
For Jove, th' immortal king, shall never die,
But reign o'er men and Gods above the sky.
The Cretans, in other words, claimed that the tomb of Zeus was in Crete. Other nations settled for claiming that they were the birthplace of gods; the Cretans had the temerity to claim that they were the grave of the highest god himself! This is mentioned in passing in a number of other sources. It shows up, for instance, in Lucian's Philopseudos:
But when it comes to national lies, when one finds whole cities bouncing collectively like one man, how is one to keep one's countenance? A Cretan will look you in the face, and tell you that yonder is Zeus's tomb.
You have to admire the boldness of it. Well, actually, you don't, and throughout the Roman world people were very far from admiring it.
In the early twentieth century, J. Rendel Harris noted a passage in a Christian commentary on Acts that might give more context for the original quotation:
A grave have fashioned for thee, 0 holy and high One,
the lying Kretans, who are all the time liars, evil beasts, idle bellies;
but thou diest not, for to eternity thou livest, and standest;
for in thee we live and move and have our being.
If something like this is really the original context, even if it has been distorted by time, one can see immediately why it might have stood out to Paul.
We can even add another layer to all of this. If we look at Diogenes Laertius's Life of Epimenides, we find this passage:
And when he was recognized he was considered by the Greeks as a person especially beloved by the Gods, on which account when the Athenians were afflicted by a plague, and the priestess at Delphi enjoined them to purify their city; they sent a ship and Nicias the son of Niceratus to Crete, to invite Epimenides to Athens; and he, coming there in the forty-sixth Olympiad, purified the city and eradicated the plague for that time; he took some black sheep and some white ones and led them up to the Areopagus, and from thence he let them go wherever they chose, having ordered the attendants to follow them, and wherever any one of them lay down they were to sacrifice him to the God who was the patron of the spot, and so the evil was stayed; and owing to this one may even now find in the different boroughs of the Athenians altars without names, which are a sort of memorial of the propitiation of the Gods that then took place.
So there were altars in Athens that were "without names" that came about because Epimenides, reputed for prophecy, let sheep go in the Areopagus to determine where they should be placed ; and we have Paul mentioning altars to the unknown God, and quoting Epimenides in a speech in the Areopagus. This seems like considerably more than coincidence.