Below, I translated the lyrics of the song Stille Nacht, Heilige Nacht by Vienna Boys' Choir from English to Spanish.
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem!
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
Lo! He abhors not the Virgin's womb
¡He aquí! No desprecia el vientre de la Virgen
Begotten, not created
Engendrado, no creado
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
See how the shepherds
Ved cómo los pastores
Summoned to His cradle
Convocados a su cuna
Leaving their flocks, draw nigh to gaze
Dejando sus rebaños, se acercan a contemplar
We, too, will thither
Nosotros también iremos allí
Bend our hearts' oblations
Inclinaremos nuestras ofrendas de corazón
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
Lo, star-led chieftains
He aquí, guiados por estrellas
Magi, Christ adoring
Los magos, adorando a Cristo
Offer Him incense, gold and myrrh
Le ofrecen incienso, oro y mirra
We to the Christ-child
Nosotros al Niño Cristo
Bring our hearts' oblations
Traemos nuestras ofrendas de corazón
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
Child, for us sinners
Niño, por nosotros pecadores
Poor and in the manger
Pobre y en el pesebre
Fain we embrace
Deseamos abrazarte
Thee with love and awe
Con amor y reverencia
Who would not love Thee
¿Quién no te amaría
Loving us so dearly
Amándonos tan tiernamente?
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
Sing, choirs of angels
Cantad, coros de ángeles
Sing in exultation
Cantad con exultación
O sing, all ye citizens of heaven above
Oh cantad, todos vosotros ciudadanos del cielo
'Glory to God
'¡Gloria a Dios
In the highest'
En las alturas!'
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem!
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor
Lord, we greet Thee
Señor, te saludamos
Born this happy morning
Nacido en esta feliz mañana
Jesus, to Thee be all glory given
Jesús, a ti sea toda la gloria dada
Word of the Father
Palabra del Padre
Now in flesh appearing
Ahora en carne apareciendo
O come, all ye faithful
Oh venid, fieles
Joyful and triumphant
Gozosos y triunfantes
O come ye, O come ye to Bethlehem
¡Oh venid, oh venid a Belén!
Come and behold Him
Venid y contempladle
Born the King of Angels
Nacido Rey de los Ángeles
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
O come let us adore Him
Oh venid, adoremosle
Christ the Lord
Cristo el Señor