It isn't easy finding truly FREE music that is legal for your videos and podcasts. Though this site does not have a lot of specifically Christian music it does have many instrumentals that can be used in videos and podcasts. In addition, it is one of the most honest, easy-to-use, free music sites I've looked at.
Below is a short video that shows how easy it is to select, download and give proper credit to the songs you choose. This is the site I used for the music for the POWTOON video I created . I simply downloaded the music from ccmixter and imported it into the POWTOON file. I copied the attribution and put it in the YouTube video file and on my website. Super easy--I may try putting music on some more of my videos in the future.
Here is the site: http://dig.ccmixter.org/