Unfortunately, it handles this question with all the grace of a sledgehammer.
First of all, God. It’s hard to really get a handle on Henry Cavill’s Clark Kent, the chisel-jawed hero who saved Earth from alien invasion in the previous film. He’s handsome and suave, flies around with panache, and is generally a complete blank of a character. The world sees him as an Olympian hero and erects statues of a great muscled form condescending from on high to save humanity. It’s no accident the film came out on Good Friday: it includes a sequence of Superman lifted up amid death-masked worshippers, a perverse resurrection. It seems less like gratitude and more like a cult.
Because simple heroism doesn't exist anymore, worship begins to turn to suspicion. In the aftermath of the destruction caused by Superman’s initial rise (narrative cruelty in the first movie much maligned by film critics), people are beginning to question whether he really is such a Boy Scout. Can the people trust him to handle his power rightly? What defense can we have against him?
In humanity’s corner is Ben Affleck (who's terrific) as Batman. An older, weathered dark knight, he traffics with gangsters, thieves, and terrorists to track down the red-caped god. Unlike Superman, his origin is in tragedy, a fact emphasized from the first moments of the story. Bruce Wayne’s childhood was brought to an abrupt end with two gunshots in an alleyway—an ignominious and meaningless crime that erased the lives of his parents. Young Bruce, screaming, crumples to the ground beneath a billboard promoting Excalibur, his destiny bequeathed to him as one untimely born—not as a man of maturity, but as a boy prematurely bereaved. (Contrast with Superman, who was raised by loving parents and therefore still maintained beliefs in destiny and meaning.)
Forged in tragedy, this hero has a massive chip on his shoulder and a settled cynicism about blithe, clean-shaven heroes like Superman. Jesse Eisenberg (who is not terrific) as a hyper Lex Luthor is just as bleak: “Devils don’t come from hell beneath us. They come from the sky.” When asked to introduce himself, Luthor says he is…“just a man.”
These are all reasonably interesting issues, but the movie really has no idea how to deal with them. We're Americans, so we have to start with politicians attempting to rein Superman in (cuz democracy). That solution is playing around with, and then dropped abruptly (Mrs. Incredible gave it her best go, quoting Ian Malcolm almost exactly). Batman brought to bear his fists and ability to have wacky dreams that have nothing to do with the plot but do set up other franchise movies. Lex Luthor...well, I really have no idea what he does, but it's weird, and ends up being something totally ridiculous.
In the end, Batman and Superman's interpersonal issues are solved when the two of them recognize an obvious fact: Superman is not, in fact, God (just to show how Marvel is superior, Captain America sorted this theological problem out in no time flat). That this involves the two of them bonding over - should I spoil this? I'm going to spoil this - the names of their mothers is about the lamest thing the film could come up with (taking notes from Chris Carter, maybe) to solve its problems.
Maybe it would be different if I cared about the characters, but Superman is boring, and while Affleck is good, he gets very little help from the script. Other characters? Amy Adams tries. Diane Lane is there for five seconds. Gal Gadot is more interesting than either of our brooding titular heroes, but is completely superfluous to the plot. Alfred, who looks like Eric Metaxas, doesn't really bring much gravitas or emotional weight to the story.
As far as emotional weight goes, the closest thing we get is the way the film ends, which does, I'll admit, pack some punch. But not enough. Goodness and power cannot coexist, the film claims darkly. Everyone is corrupted in this world! Sure, sure. Very trendy and not terribly original, nihilism. Give me a sunset, any day. Or just a red cape.