yes, the content of the lyrics is what separates this from the worldly music of the same genre.
there is, also, scriptural support for making music that is of high quality, not just that the lyrics present and/or agree with the gospel:
Sing unto him a new song;
play skilfully with a loud noise.
(Psalm 33:3)
for me personally, i never liked this style of music at all until some Christians i met online made me listen to some. i always said, i would like rap if there were no lyrics -- now the lyrics are the part that i really like best, that moves me, but i also appreciate the artistry of the 'beat' too.