For me it is some old xian rock bands (mine being one of them). I like the music we made, but the lyrics embarrass me to no end. But as much as people want to make xian rock out to be pussy music (which I have to agree it is), there are some gems out there. Barnabas - Approaching Light Speed and Feel the Fire are amazing albums. Rez band was good for a stretch. And the first LifeSavors album with Mark Krischak is a punk masterpiece in my opinion, regardless if the words make me throw up a little now.
Handle's "Messiah"... "Ave Maria"
I also like a lot of country music, which always has jesus or god references...
Your mention of country music reminded me: I very much like a lot of the music of "Trio" with Dolly Parton, Linda Ronstadt, & Emmylou Harris. Three beautiful voices.
A couple of their religious tunes are "Hobo's Meditation" and "Farther Along".
It's not popular music, but "Comfort Ye," the first solo of Handel's Messiah, has been a favorite of mine for a while and one that I occasionally sing along with. I can't do the fancy voice-work that some soloists bring to it, but otherwise it has a relatively simple quality to it that I enjoy.
Being a life-long fan of Kansas and practically a worshipper of Kerry Livgren, they both fall into this category for me. Kansas was never technically a christian band, but since Livgren was the best writer of the group, once he got religion, his lyrics did too.
god gave me you <-- this song is popular in our country and i also love the voice of bryan white