This of course is nothing more than the Apostle Paul "quote mining" in order to prove his own bias and to 'glorify' Jehovah's name and to push his own brand of religion. Exactly what the Watchtower Society does today when it cherry picks 'quotes' of scientists and scholars that seem to support the Societies own viewpoint. This quote is taken from a poem by Epimenides (See Wikipedia for a fuller biography) who wrote in defense of his god Zeus:
"They fashioned a tomb for thee, O holy and high one
The Cretans, always liars, evil beasts, idle bellies!
But thou art not dead: thou livest and abidest forever,
For in thee we live and move and have our being."
The Apostle Paul was quoting from a religious poem that glorified Zeus and was putting down the Cretans for not believing in him. Probably not a very good source of evidence for the 'Christian' Apostle Paul to use in describing the character and state of honesty of every person in Crete.