Looking for G-d in Harry Potter

I'm almost afraid to finish this book, "Looking for God in Harry Potter" by John Granger. First, I've only read one Harry Potter book, I know hard to believe, but fiction is not something I read. I used to read a lot of sci-fi fiction in high school and college, but once I hit grad school, no more. Second, I've seen most of the Harry Potter movies, but knowing how movies go, there is a lot that is left out. Granger's book mention things I cannot conjure up from my memory of the films, so it must have been left out.
In somethings I think Granger is stretching a little too far finding the symbols of Christ everywhere. The stag is Christ. The unicorn is Christ. The red lion is Christ. The centaur is Christ. That's a lot of Christs or symbols of the Christ running around. I could prove myself wrong when I re-read the books and say, "of course! The [random creature] is a symbol of Christ [doing something]."
I did hit something that made me finally whip out the pencil and write in the book (I do that, write in the margins). There is a scene where Harry observed Lord Voldemort drinking the blood of a unicorn the Dark Lord wounded (killed?). A centaur explained that "The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something pure and defenseless to save yourself, and you will have a half-life, a cursed life, from the moment the blood touches your lips." Granger then compares this to 1 Corinthians 11: 23-29 and thus highlights a portion for me that, I hate to say, seems new. That being

1 Corinthians 11:25-27 (New International Version):New International Version (NIV)
25In the same way, after supper he took the cup, saying, "This cup is the new covenant in my blood; do this, whenever you drink it, in remembrance of me." 26For whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes.
27Therefore, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord.

This now makes me a little hesitant to go to church today. The Eucharist is the main draw for me, the presence of his body and blood. And well. I know I'm not worthy. And seriously, this is my first time realizing there was a restriction on the communion. The whole 'unworthy manner' thing is news to me. I might have read it before but never gave it much thought.