It's a religion that places a huge amount on emphasis on rational belief. They like to take mysticism out of it as much as possible (except where it comes in handy, like explaining how God uses the FDS to provide new light....).
I confess I found many of their teachings appealing because they made sense: why God wouldn't create humans with the intention that they'd die, why an intelligent creator suggests an intelligent purpose ...
Other teachings I just learned to swallow because they were part of the package: that God has an organisation, that only 144,000 go to heaven, that a complex set of hidden clues pointed to 1914 being a pivotal year in human history etc etc. And blood and birthdays were part of that as well.
The problem is their teaching methods, restricting information to a very narrow, predetermined course, with pre-provided answers to the questions they ask, is a very clever, and very insidious method of teaching. Indoctrination, really. You have to ACCEPT certain points before you can move on to the next step. It simply forces people to accept the whole range of teachings without room for alternative views. And that's where the mind control starts.