Definitely the biggest thing for me has been the different redemptive analogies and themes O'Connor was able to represent through the use of the grotesque and with the aid of some pretty uncomely characters. I never considered being the possibility of doing something like this having been under the previous understanding that experiences with grace were to be paired with a happy fuzzy endings... a change in action. I had mostly only been exposed to that which O'Connor considered "soggy literature." She does something so unique in that her focus on the encounter with grace transcends the after effects of grace... which is the most important part of the whole thing! It matters if you have truly had an encounter with grace or not! What happens next can't even be considered if the experience with grace has never occurred! And this grace doesn't look the same way as it usually does! This has lead me to a whole new perspective of looking at truth and this collision also changes the perspective of her characters... Hazel Motes, Mrs. May, Hulga... then BAM (literally for Mrs. May.)
I think mostly it will change my idea of writing, especially in the "Christian genre." O'Connor was bold to write about real, dirty things. This was so bold and brave. And there is light.
On a side note in the subject of the experience of grace not looking like what we think it should ... I am reminded (on a smaller, but somewhat similar scale) of some of Ted Dekker's works and the grace his characters face. If you are familiar with him, in his book Thre3, a character has an encounter later in him life with an angry childhood bully who has come back for the blood of he and his childhood friend... and after many attempts on his life and much drama it is discovered that he himself suffers from a multiple personality disorder... a sickness of the mind that had tormented him as a child, inventing a friend and an enemy. This man's encounter with grace, like O'Connor's friends, results in the revelation that all the destruction has been from he himself.