Alot of emphasis so far here has been about hitting the right note, getting a good speed, being precise, and so forth. But we must remember that music is not just about notes, but about transmitting emotions and worship to the congregation. To do this, we have to feel the song as we play it, we have to sing with our instruments and transmit our worship into sound.
For the acoustic, this comes out in two ways
i) Volume. Vary your volume according to how the rest of the band is feeling the song. Usually the verse will be quiet, and the chorus/bridge will be loud. Consciously listen out to how the drummer is building up, and feel the song together with him/her.
ii) Groove (or rhythm). Play together with the drums - you definitely must listen out, and even look at the drummer's arms. What happens is that you have to synchronize the drummer's kick and snare with your up and down strokes. Very generally, do a strong up/down stroke when there is a kick or a snare, and do softer strokes in between to fill up the rhythm gaps.
Here's an example I did with The Stand. Watch out for how I vary my volume (esp the first part without the music), and how I try to play with the drums. Download the chords here.