Epigraphs are like little appetizers to the great entrée of a story. They illuminate important aspects of the story, and they get us headed in the right direction.
"The proper response to love is to accept it. There is nothing to do." – Archbishop Anthony Bloom
So what's up with the epigraph? Well, we're not really sure, but if we had to guess (and that's what we're here for), we'd say that Shepard's playing with us a little bit with this epigraph. The quote from the archbishop seems to suggest that love really isn't that complicated—someone gives it, and the person receiving it should just shut up and take it and write a nice thank-you card. Easy, right?
Well, not so much for the folks in this play; love is a big complicated mess for them. Also, in the case of May and Eddie, there are definitely certain kinds of "love" that probably shouldn't be given or accepted, if you catch our drift.
Sure, maybe Shepard really just wants to make an "it's all good" kind of statement about how love is just love and should be taken as such… but the gritty, down and dirty, complicated situations that are the heart of his play kind of work against that reading.
In fact, the suggestion is that love gives you quite a lot to say and do—even when incest isn't involved.