Lyric discussion by HASJ 

Cover art for Tapestry lyrics by Protest the Hero

I can be totally wrong and after reading the lyrics and the song is pretty much about futility and wasting your life, I still hear

"Cancer just keep falling out and Christians keep getting fatter" lol

Futility can be epic, PTH just proved that to me with their best song to this day.

No, it definitely doesn't say that. Listen closely to that line. when he says, "Keeps getting fatter", "Keeps" has a clear "S" sound, which would not fit into your interpretation.

i thought it was christians too but i do here the plural possessive "s"

That and Rody generally doesn't write about religion, to which I'm glad, being Christian.