Writing contemporary Christian worship music involves more than simply putting religious words about God into your song’s lyric. Yes, worship lyrics have to do with The Lord but for your song to be played on Christian radio as well as get used in church worship services, there are some “rules” of sorts it would be wise to follow.
Not all songs played on contemporary Christian radio stations are useful in corporate worship. Worship lyrics tend to emphasize a personal relationship with God by using “I” and “you” frequently. A song titled “I Love You Lord” would be an excellent choice for a worship tune, “God is a Great God” would be less likely to garner favor.
The melodies tend to be fairly simple and the singing range usually isn’t very challenging. If your song is something only Mariah Carey can sing. your potential market will be small. Write something everyone in the church can sing!
As far as the music, simple chord progressions are a plus. Many worship bands are volunteers, not accomplished musicians. Make it easy for them to play!
Also most worship leaders like to have at least one to several songs that “build” in each service. Typically the bass may play whole notes or half notes early in the song, or even sit out for a while. At some point as the song enters a new section, the rhythm shifts to pulsing quarter notes. Finally the song peaks with the rhythm section pounding out eighth notes. Once achieved, the song may revert to a very simple rhythm or even voices-only to finish out.
Many worship songs repeat sections far more times than you’d typically hear in most rock or pop songs. Bridges, for example may repeat as many as five or six times.
So now you have a clue about how to write a worship song, how do your sell it? Or do you even want to? Few secular artists have a problem with profiting from their work but many Christians are conflicted in this regard. If making money from your worship songs bothers you perhaps you should assign all profits to a Christian based charity?