Lyric discussion by where_the_party_is 

Cover art for I'll Let You Live lyrics by Taking Back Sunday

This is a really good closing for an amazing album.

Anyway, i think it's talking about all these vices that someone has, ("Came as a gift from a good friend (a good friend) That dissaproves (but understands) To represent and actively encourage all of my worst habits They all are proof that we are both capable Of the most terrible things Don't test me") or something that happened that was particularly negative. He feels far away from the person because (s)he doesn't understand that "there's no stopping" him.