"Face My Enemy" does nothing to advance the plot, but it does give us an awesome fight sequence -- which works if that's all you're watching for.
"Face My Enemy" is the first episode of Season 2 that feels entirely superfluous, in terms of the "big story" stuff: Nothing really advances, there are teases but no major markers crossed in terms of the characters' developments, the one thing that looks like a major reveal turns out to be one-off misdirection, and there's essentially no Marvel Universe ephemera to parse out -- hence why there's no breakdown at the end of this article.
Ideally that wouldn't matter if the writing/direction/acting was on point, but let's not mince words: Marvel tie-ins and its own meta-story are the only things (apart from a group of characters who took almost a full season to become interesting) that keep Agents of S.H.I.E.L.D. from being a lower-budget NCIS with more exaggerated spy gear.
It starts promisingly enough: A group of priests arrive at a fire-devastated Miami church to investigate the "miracle" of a Renaissance-era painting of The Virgin Mary & Child having somehow survived the blaze unscathed. Already I'm interested: The supernatural side of Judeo/Christian canon does exist in the traditional Marvel Universe (usually focused on the demonic side), and I've been hoping to at some point see how that dynamic "works" in the Cinematic Universe... but it's not to be: The "Miracle Painting" seems to have alien writing on the back of its canvas.
Oh well. The actual setup is that S.H.I.E.L.D. now needs to retrieve this Miracle Painting from a charity art auction that General Talbot also appears to be attending. However, it's quickly apparent that the episode's main reason for existing is to do an old-fashioned Mission Impossible-style spycraft romp with Coulson and May infiltrating a fancy-dress party, all the better to separate them from the rest of the team and tease out more hints as to the actual nature of their (apparently) shared backstory and drop a new ticking-clock on us. Coulson wants May to kill him and take over as Director if the GH.325 still in his system does to him what it did to John Garrett.