German (and Latin):

In dulci jubilo
Nun singet und seid froh!
Unsers Herzens Wonne
Leit in praesepio
Und leuchtet als die Sonne
Matris in gremio
Alpha es et O, Alpha es et O!

O Jesu parvule
Nach dir ist mir so weh!
Tröst mir mein Gemüte
O puer optime
Durch alle deine Güte
O princeps gloriae
Trahe me post te, Trahe me post te!

O Patris caritas!
O Nati lenitas!
Wir wären all verloren
Per nostra crimina
So hat er uns erworben
Coelorum gaudia
Eia, wären wir da, Eia, wären wir da!
Ubi sunt gaudia
Nirgend mehr denn da!
Da die Engel singen
Nova cantica
Und die Schellen klingen
In regis curia
Eia, wären wir da, Eia, wären wir da!

English:

In sweet jubilation now sing with hearts a-glow!
Our delight and pleasure lies in a manger
Like sunshine is our treasure in his mother’s lap
Thou art Alpha and Omega! Thou art Alpha and Omega!
O tiny Jesus, for thee I long always;
Comfort in my heart’s blindness, O Best of Boys
With all thy loving kindness, O Prince of Glory
Draw me after thee! Draw me after thee!
O love of the Father, O gentleness of the Son:
Deeply were we stained through our crimes;
But Thou for us hast gained the joys of the heavens
O that we were there! O that we were there!
Where are the joys? In any place but there?
There are Angels singing new songs
And there the bells are ringing in the court of the King
O that we were there! O that we were there!