Yes, it's tough, but without allowing it, we may not have been able to eliminate the parking necessary to put in the bike lanes in the first place. (At least that's my understanding of the history.) Your options are:

1. Join them: http://www.churchparkingforatheists.com/
2. Organize a couple hundred bikers to park in the bike lanes at strategic times, which will only escalate things and create public ill-will toward a complete streets policy that barely has a toe-hold in local government.
3. Live with it on the weekends (they have weddings on Saturdays too) and enjoy having a buffered bike lane on your weekday commute.

IMHO, bike lanes that are entirely blocked are better than the partial blockages caused by delivery trucks and maintenance vehicles because you don't have to weave in and out of traffic. I'd really love to concentrate our enforcement efforts on those isolated-but-repeat offenders.