My thought is to play however it feels like it should be to you. I've heard about four different versions of "Amazing Love". None of them were identical, and they all sounded good to me.
Otherwise, don't try and get it just right immediately. Just go with down strums on 1 and 3 counts while singing. Slowly add in additional strums, up or down, that "feel" right to you. Develop it over time instead of all at once.
Remember that the Newsboys are an entire band. You are a single guitarist. You will not mimic an entire band with a single guitar no matter how good you are. The best guitarist I've ever heard cannot make his guitar sound like a saxophone. So, just give it a go and do your own version.
- Zurf
Granted B chord amnesty by King of the Mutants (Long live the king).
If it comes from the heart and you add a few beers... it'll be awesome! - Mekidsmom
When in doubt ... hats. - B.G. Dude