I think the offer to participate in some tactical and crisis training is a great opportunity. That type of training, especially with a quality instructor, will really benefit you.
As we know churches are not off limits to CHL holders unless properly posted. Your only concern on carrying would be if your employer prohibits it for employees. If they don't I would carry as soon as you get your plastic.
As far as security goes, if that means being vigilant and prepared mentally and phisically to stop a threat to the church I think that's great. If they want you to condut some sort of security work you should look into the legaql requirements. Here is a link to the Occupations Code:
http://tlo2.tlc.state.tx.us/statutes/do ... 702.004.00" onclick="window.open(this.href);return false;