Violating the 8th commandment in the name of musical style is certainly a bad idea. Therefore, rather than speak ill of or otherwise sound a negative note (ha ha) toward another musician's work, I'm going to denigrate my own.
As I see it, popular worship music has a few basic rules. Let's look at some now, and generate a composition that fits them:
Try not to be too serious
Emphasizing themes of community and togetherness is a safe bet. Works well for the Beatles ("Come together,") as well as any number of hits since then, and of course, in the music of the emergent church. It might be good to add a contrasting section that throws a little doubt in there, but not too much! Most popular music emphasizes the importance of emotions over intellect, so make sure your heart is in the right place.
Keep it Ambiguous
Your market is anyone calling themselves a "Christian." You don't have to be Christian, nor do you even need to know anything about Christianity, as long as you include some general "feel good" themes. Be careful not to get too specific, though, because those Christians don't always agree. The worst mistake would be to alienate part of your market segment and scare them away from your record label.
Repetition, repetition, repetition
People don't seem to mind mindless repetition. In fact (see the next rule) if you don't repeat stuff enough, people will get confused and they won't like the piece until they "learn" it, which might take multiple tries. In this hyper-competitive environment, who can afford that? Beat 'em with a sledge hammer!
Don't expose the listener to more than a couple of sections
If you can't discern the form the first time through, it's probably too complex. A simple A-A-B-A works well, as does a Verse/Chorus approach. Anything more elaborate than that will result in confused singers/listeners, who may go off in search of something easier to swallow.
Borrow heavily from earlier sources so the music doesn't sound too new or challenging
Your singers/listeners may approach your music with a limited palette. Try to aim at their demographic. For much contemporary praise music, middle-of-the-road (think: 1970s AM radio, soft-rock, etc) style is preferred. Lots of eighth-note arpeggios with minimal harmonic novelty.
I think we're ready to go. Here's what I've come up with. How did I do?