Can anyone recommend good Worship Service software for a Mac?
All the ones I've seen make you export keynote files to powerpoint and the Pastors' don't want to do that.

Pro Presenter is Great.

You can use KeyNote and pro presenter submits to it.

Then when the presentation is over it switches back.

It works beautifully.  My pastor uses his iPhone to switch the slides himself in keynote, and ProPresenter has as many or as little features as you need. From simple white text on black background all the way to a full blown video production. (some additional materials required).

It's pretty much the industry standard on a mac, and soon will be on the PC as they have just come out with version for the PC.

We use it bare bones, so I'm sure someone else here can school both me and you on it.

I will second ProPresentor. . .  used it at the last company I worked for and think there's nothing better. . .

yeah, we're still on ProPresenter 3 here, but its absolutely fantastic. It's all I've used so I cant really compare it to anything else, but I've never had a second's problem with it. It's the reason I moved to mac.

I would highly recommend ProPresenter also. It is extremely user friendly, which makes it very easy for volunteers to use as well.

Yep, Pro Presenter is the defunct software of choice. I do wish there was a better choice though because the work flow is a little herky jerky sometimes depending on what demands you put through it. If you want to run live video feed to the projection you will have to first go through a switcher because the camera option has a major latency issue. Or, you could buy an expensive converter card to keep the feed in sync.
It's still a pretty good overall product for prosumer level work.