It had flaws
This show had an interesting theme/story and the tone of the show was pretty spot on with the story, but there were flaws. One that stuck out to me straight away was how they just expected us to instantly believe Christina being around was changing the town. We don't really see how they were before, she washed up pretty early in the pilot and we're just told the town got weird with nothing to back it up. The first episode really could have focused more on the town and then did the Christina washes up thing and had it end right with the scene of her waking up and all the lights comming on. It wouldn't have been much but it might have been enough to demonstrate the towns dynamics pre-christina.
Judy is so inconsistent. She goes from liking Chris to kicking her out to be fiercely loyal to wanting to kill in a very short span of time and while it could be said to be an influence from Christina's prescene it's all a bit messy. She was like the script writers rag doll written to fit any situation but never having been a fleshed out character.
I praise the show for not going over board with the evil characters or the good characters (granted what we're first shown are the good characters, the vatican soliders and the human sacrafice people originally come off as the good characters but is kinda revealed they aren't by Meg and Terry's dad). The evil characters were at times a bit cliche but no biggie.
There wasn't any solid reason of "why?" and there were a couple inconsistencies. In one episode it's made out like Christina is the first of her kind, that she's here because people have lost faith...a couple episodes later Boyd and Wes are talking about previous anti christs and how they always failed because of gods chosen one. The motivations of either side are what? At one point there's talk about Satan wanting the world cleansed because the experiment failed and he wants to start again or something....yet Christina has choice, she isn't necesssarily going to "cleanse" the world even when she is on the dark side she was all about getting what she wanted. How'd the experiement of earth fail? If the church and all that aren't really right like was suggested then what really is the motivations of Satan and God...although that probably would have tuned up in a later season. The whole bigger picture was just absent, the focus was all on Christina, without the bigger picture we can't really understand her or her role to any significant degree.
I would say the show was rushed, but they knew they were cancelled so whatever.