Heaven is an end - it's the end. It's also a euphoric state of being - "I'm in heaven". "Can't face heaven, all heavenfaced.": He can't face that his relationship has become cold, dead, because he is still caught in this euphoric love - he's still "heavenfaced".
"She's a griever, my believer.": She grieves a lost aspect of their relationship, believing that it can come back - that He can be what he once was, that "He" can come back.
Berninger sings about being trapped in a nostalgic relationship; they stay together in memory of their heavenly history - unable to face their relationship's end.
Heaven is an end - it's the end. It's also a euphoric state of being - "I'm in heaven". "Can't face heaven, all heavenfaced.": He can't face that his relationship has become cold, dead, because he is still caught in this euphoric love - he's still "heavenfaced". "She's a griever, my believer.": She grieves a lost aspect of their relationship, believing that it can come back - that He can be what he once was, that "He" can come back.
Berninger sings about being trapped in a nostalgic relationship; they stay together in memory of their heavenly history - unable to face their relationship's end.