What does the poem "On the Life of Man" by Sir Walter Ralegh express?

"On the Life of Man" by Sir Walter Raleigh has a message
similar to Shakespeare's famous statement in As You Like It Act II
scene vii:

All
the world's a stage,
And all the men and women merely players:
They
have their exits and their
entrances;

To look at it
closely, let's first clear up some of the phrasing as it is explained on href="http://www.luminarium.org/renlit/lifeman.htm">Luminarium.org: "play
of passion" refers to a dramatic play, meaning a dramatic life; "musick of division" is
the music that divides the acts of a play; "tyring houses" the rooms where actors change
costumes (attiring; changing attire); "spector" is a word play misspelling of spectator
that combines it with specter (ghost), thus bringing up an allusion to audiences living
and dead.

In a poetic conceit (i.e., a long poetic
comparison of two unlike things) comparing life to a play, Sir Walter Raleigh is saying
that life is a drama and that the moments of mirth (happiness and laughter) are fleeting
moments, as fleeting as the music that marks the space between acts of a play. Having
dressed for the drama play in the womb, we enter our short stretch of life, which
Raleigh ironically compares to a comedy. You know it's ironic because the whole conceit
compares life to a painful drama.

The next four lines of
the ten line poem written in five couplets compares God ("Heaven the Judicious sharpe
spector") to the audience at the play, saying God takes note of those who do wrong ("who
doth act amisse").  Sir Walter ends the conceit by comparing the grave, which is a
metaphor for death, to the final curtain ending a play.

In
the final couplet, he indicates that he has described how we march through our dramas to
our final and eternal rest in the grave. His final note implies that while a play has an
end but begins again and even again, our final curtain at the grave is in earnest with
no repeat performances ("we dye in earnest, that's no Jest.").