When judges chose the EC writings for the anthology, are the stories and poems generally spiritual in nature?
No, entries do not have to be spiritual at all. They just have to come from a Christian point of view. In other words, the main character can't be a very appealing devil who everyone loves. Or the entry can't appear to be condoning a sinful lifestyle. That sort of thing. Most entries do tend to have a fairly obvious Christian theme, but that isn't taken into consideration at all when judging.
And for the Challenge, are the entries judged as the come in, or do you wait until all are submitted?
They are judged as they are submitted. It would be impossible to do it within the time frame otherwise. The judges on duty for that week have access to a behind-the-scenes area and start judging as soon as the first entry arrives (or as soon as they get the password to the area).
They have until the Sunday morning after entries close to finish all their reading and rating, and then return their rating sheets to me. So all up, they have about ten days to do all their reading and rating. Mind you, the big rush is always in the last day or two, so they do end up with a lot of reading in those final days.