One of my very secular family's Christmas traditions for some years now has been a playing of Beethoven's 9th Symphony, which, while not explicitly Christmas-related, has always struck me as good enough to (almost) justify the existence of religion.
In that spirit, here is a (semi-decent) translation of the gorgeous German poem that inspired the symphony:
Ode To Joy
by Friedrich Schiller
Joy, bright spark of divinity,
Daughter of Elysium,
Fire-inspired we tread
Thy magic power re-unites
All that custom has divided,
All men become brothers
Under the sway of thy gentle wings.
Whoever has created
an abiding friendship,
Or has won
a true and loving wife,
All who can call at least one soul theirs,
Join in our songs of praise;
But any who cannot must creep tearfully
Away from our circle.
All creatures drink of joy
At nature's breast.
Just and unjust
Alike taste of her gift;
She gave us kisses and the fruit of the vine,
A tried friend to the end.
Even the worm can feel contentment,
And the cherub stands before God!
Gladly, like the heavenly bodies
Which He set on their courses
Through the splendor of the firmament;
Thus brothers, you should run your race
As a hero going to conquest.
You millions, I embrace you.
This kiss is for all the world!
Brothers, above the starry canopy
There must dwell a loving Father.
Do you fall in worship, millions?
World, do you know your Creator?
Seek him in the heavens,
Above the stars must He dwell.