"Pilgrimage, in its essence, is travel for transformation," says Greenia. "It's when you’re open to be transformed by what you see."
In an upcoming film called "The Way," starring Martin Sheen and Emilio Estevez, Sheen's character plays an American doctor who, after the death of his son, sets off on a medieval pilgrimage trail in Spain called El Camino de Santiago. Sheen’s character is at first conservative, well-to-do, and set in his ways. But he becomes a softer, better version of himself along the trail. And that, says Greenia, is the point of pilgrimage.
Every summer, Greenia takes his students on that same 500-mile trail.
"We've crossed the medieval bridges, the medieval landscapes; we’ve endured medieval weather too."
Greenia, who has organized a recent screening of the film, says that in medieval times, people went on pilgrimage for various reasons.
"You can go to fulfill a vow. You can go to ask a favor, such as good health for yourself. You could go to ask for fertility for your wife."
Sheen's character in the film has his reasons for walking the trail too – not just to deposit his son's ashes along the way, but to better know the son he lost. And he's also walking to redeem himself, says Greenia.
"That journey is a journey of reconciliation, of redemption, of carrying the dead with you, in order to restore your own life and make it whole again."
"The Way" is set to be released in September.