This tab provided by 33 Miles on their website at 
http://33milesonline.com/wp-content/uploads/2012/08/01-O-Come-All-Ye-FaithfulSing-to-the-King.pdf

Tabbed here for usage of those who would like easy transposition.

O COME ALL YE FAITHFUL/SING TO THE KING
(As performed by 33miles)
GUITAR INTRO OVER 'A'
ALL IN...
A A A  D D E A
A A A  D D E A
VERSE
A   F# E
O come all ye faithful; joyful and triumphant
     F#   E   F# E
O come ye; O come ye to Bethlehem
F# A      bmin
Come and behold Him born the king of angels
    F#
O come let us adore Him
    bmin
O come let us adore Him
    D    E A/C# D E       A A A  D D E A
O come let us adore Him  Christ the  Lord
A  F# E
Sing choirs of angels sing in exal- ta- tion
F#        E   F#     E
Sing all ye bright hosts of hea- ven above
F#   A     bmin
Glory to God all glory in the highest
    F#
O come let us adore Him
    bmin
O come let us adore Him
    D    E A/C# D E      
O come let us adore Him  Christ 
CHORUS
A
Come let us sing a song
bmin       G D
a song declaring we belong to Jesus
Asus A     Asus  A Asus A
He's all we need
A
Lift up a heart of praise
bmin       G D
sing now with voices raised to Jesus
Asus A     Asus A Asus A
sing to the King
INSTRUMENTAL
A A bmin bmin G D Asus A     Asus  A Asus A
CHORUS
A
Come let us sing a song
bmin       G D
a song declaring we belong to Jesus
Asus A     Asus  A Asus A
He's all we need
A
Lift up a heart of praise
bmin       G D
sing now with voices raised to Jesus
Asus A     Asus  A Asus A
He's all we need   (Yeah, He's all we need)
A
Come let us sing a song
bmin       G D
a song declaring we belong to Jesus
A A A  D D E A
Sing to the King (hey yeah...)
A A A  D D E A A
       O come let us adore Him...