Lyric discussion by @nthony 

Cover art for Come In Please lyrics by Edward Sharpe and the Magnetic Zeros

To me this is saying that In spite of all the complex highbrow philosophical & artistic doodling on death, the only real thing we need to concern ourselves with is how we deal with the conscience we are left with on our death bed or beyond (across the line) . The rest is superfluous ego driven diversion.

My Interpretation