Making the threat behind "Blessed Are The Damned" less evil than it is misguided is a nice touch, implying that Zachary's followers are simply misguided without crushing their faith. Even Zachary gets a rare forgiveness from Constantine himself instead of being punished for toying with powers he didn't understand. In fact, the show generally seems to suggest that Heaven might be a better place than Constantine's cynicism allows him to believe. If this were the comics, Constantine's view would be fully vindicated and Manny would turn out to be an angelic sociopath. While the shift probably has more to do with not alienating religious audiences than anything else, it does make the universe a little more complex than the "everything is evil except humans" approach most supernatural shows tend to take.
Not that this stops the episode from being as cliched as any other small-time religion episode. As soon as entering the throngs of the faithful, Constantine and Zed immediately descend into your typical "is faith enough" conversation that reflects their personality types. This kind of debate has been played to death in similar shows, and this version adds very little of note here. Zed suggests that something in her past happened that makes her want to believe in goodness. Hellblazer fans will probably know what she's talking about, but since we're not likely to explore that thread until the finale, we're just left hanging.
Still, the episode has some fun moments, my personal favorite being a ghoul attack in the middle of a mass baptism. "Blessed Are The Damned" also breaks out one final twist when it turns out that Imogen wasn't fully honest: yes, she's an angel, but she's a fallen angel. Helping her restore her wings accidentally unleashed one of the most powerful creatures Constantine has shown to date, although it happens so late in the episode she doesn't have much time to show off her powers. But for a few moments, it's an exciting sequence that Constantine will hopefully revisit again.
This show is at its best when it toys with viewer expectations to surprise us with something bigger. With only a handful of episodes remaining this season, I'm hoping it will continue to take full advantage of that trend.
Bottom Line: "Blessed Are The Damned" is Constantine's required faith healing episode, so odds are you fully know what to expect. Constantine and Zed's character arcs fall into the typical "cynical skeptic vs optimistic believer" debates we've seen countless times. There are a few good supernatural twists that help the episode stand out, but they tend to be too few and far between to make this an especially great episode.
Recommendation: The monster bits are fun, and it establishes minor plot points that will probably be significant later on, but don't feel too bad if you happened to miss this week's episode.