Lyric discussion by idkwtfwtf 

Cover art for Comfort Betrays lyrics by As I Lay Dying

this song is about a "good" friend who left someone hanging.

you sat and watched as I nearly destroyed myself never had I felt so betrayed that you would sacrifice my life for no more than your comfort

"nearly destroyed myself" means someone made bad choices "that you would sacrifice my life for no more than your comfort" means that the "friend" just stood around or actively participated in "destroying" this person. or he left him during a rough time.

and now your love means nothing nothing to me your love means nothing to me nothing to me

the person no longer trusts the friend

you are a coward the antithesis of a friend take action before there is no one left to defend

telling the friend how much he sucks and to change his ways so he doesn't hurt other people the same way he hurt this person

I would have stood by you I would have stood by you right to the gates of hell

he is telling the friend he would have stuck with him through thick and thin. unlike the friend, this person would not bail on him and leave him to suffer.