How does The Prince symbolize the humanist revival of Greek and Roman texts and promote secular models?

Machiavelli was a true child of the Renaissance. He was a thoroughgoing humanist who looked fondly to antiquity for models of learning, wisdom and statesmanship. The Prince stands as a monument to the rediscovery of ancient Greek and Roman texts. Yet Machiavelli was also a humanist in the broader sense in that he set forth a vision of political philosophy uninfluenced by prevailing standards of Christian morality. Indeed, it was this feature of his magnum opus that made Machiavelli's name notorious for centuries.
Both senses of the word humanism coalesce in how Machiavelli understands human nature. Prior to Machiavelli, political philosophers, in keeping with their religious convictions, tended to deal with people as they ought to be, judging political actors by high moral standards inherited from the Christian tradition.
Machiavelli's whole approach to the matter is completely different. He takes people as he finds them, as they actually are. If you want to give sound political advice to a prince, then you need to deal with a real world, not an ideal one. And in the real world politics is a messy business. Lying, cheating, stealing, repression, subterfuge and brutality are just some of the more unpleasant characteristics of everyday political life. If a prince wants to get on, if he wants to keep hold of his territory, then he needs to learn the rules of the political game, and fast. And if this means acting with utter ruthlessness, then so be it.
After all, this is what the Romans did. They understood the dictates of politics; they knew what had to be done to keep their territorial integrity intact and suppress rival powers. At no point did they allow themselves to be seduced by some high-minded ideal of statecraft. Indeed, it's telling that the Roman Empire only really began to collapse when its ruling classes embraced Christianity.
It's fair to say that Machiavelli has had something of a bad press down the centuries. His cynical, brutally realistic take on politics has been held responsible for giving succor to every tinpot tyrant, dictator and despot ever since. But beneath its superficially callous exterior there beats a profoundly humanist heart. For Machiavelli in The Prince the security and stability of the state are of paramount importance. Yet this is not an end in itself; it is a means to a much higher, and more morally elevated end. That end is the flourishing of each and every human being. It is difficult to think of a vision more in keeping with the spirit of the Renaissance.