Lyric discussion by gelpen 

The rumor is that Carey Mulligan and Marcus Mumford were pen pals when they were kids and while he was still dating Laura Marling, Mulligan came to one of his shows and was in the first row and they remembered each other and had a connection (and possibly he cheated on LM).. so here's my interpretation:

You hold your truth so purely (He's talking to/about Carey Mulligan who is christian like him--I think I read that they used to go to the same church group or something as kids so I think the fact that he met her when they were innocent children makes her represent something fundamentally angelic and innocent to him?) Swerve not through the minds of men This lie is dead (either the denial of their connection over the years, his relationship with LM or both) This cup of yours tastes holy But a brush with the devil can clear your mind (While she represents holiness and goodness to him, cheating on LM with her would be a sin) Strengthen your spine (still sometimes desire/sin can reveal truth and teach you something) Fingers tap into what you were once (he's overwhelmed by memories of her when she was a child) And I'm worried that I blew my only chance (maybe the way he went about courting Carey while he was still in a relationship really offended her? Maybe he's worried that because Carey has christian ideals and obviously doesn't believe in cheating that he's already ruined his chances with her by emotionally cheating/proving to not be worthy of her in some way?)

Whispers in the dark (his connection with her at his show, maybe back stage, catching up) Steal a kiss and you'll break a heart (He's talking to himself now--he's tempted to kiss her during their conversation and flirting but if he does, he'll break someone else's heart?) Pick up your clothes and curl your toes (He cheated... and it's the morning? This image conveys a lot of shame) Learn your lesson, lead me home (now he has to learn his lesson from his mistakes but at the same time he's heading in the right direction... I mean he did marry her!) Spare my sins for the ark (he's departing on Noah's ark--a metaphor for that he's being lifted from a lower place and feels his relationship with Carey is like embarking on a new journey that will be purer and holier --because he sees Carey as a symbol of truth and goodliness?) I was to slow to depart (He should have ended things with LM) I'm a cad but I'm not a fraud (He's a cad--meaning meaning he behaved dishonourably to LM but he's not a fraud because he didn't do it for personal game--in other words, he didn't do it to hurt her, he did it because his relationship with Carey was destined in a way or true somehow) I set out to serve the Lord. (And so he embarks on this new relationship which is tied to a promise to be a better and more faithful christian man)

And my heart Was colder when you've gone (when Carey wasn't there he was less of a pure person--LM made him colder so in a way Carey is making him better even though he did something horrible with her) And I lost my head (again he did something bad and against his logic and moral code) But found the one that I loved (but he found Carey--his soulmate) Under the sun (and he is no longer cold with her--spiritually he is enlightened by her) Under the sun

Fingers tap into what you were once And I'm worried that I blew my only chance Fingers tap into what you were once And I'm worried that I blew my only chance

And my heart Was colder when you've gone And I lost my head But still, while we are young (I think part of his justification for feeling good about his new relationship is the fact that he has been denied her for the years that they were apart since childhood and although he hurt LM he ultimately needs to embrace finding his soulmate while he still can) While we are young While we are young While we are young

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