Why not just portray it as salvation for the lost.? Portray it that God accepts you as you are, and then works to make you like one of his?
Nobody is saying you shouldn't. But being "like one of His" does not necessarily mean you have to be an organist who refuses to play anything but hymns.
The guys in Switchfoot are "His" - and if their being good at what they do in a genre that appeals to young people makes a kid more curious about Christianity and inclined to explore it, there is no harm in that.