I put this together while listening to the Hillsong United Youtube video of the 
song, I think it sounds spot on with my 12-string.
Hope you enjoy,

Mighty to Save
By
Hillsong

(capo @ 2nd fret)

(Intro.)
[C][G][Em][D][Dsus4][D][Dsus2][D]

(Verse 1)
[C]              [G]                          [Em]         [D]          [C]
Everyone needs compassion, a love that's never failing; let mercy fall on me.
[C]              [G]                        [Em]          [D]     [C]
Everyone needs forgiveness, the kindness of a Saviour; the hope of nations.

[C][G][C][D][Dsus4][D][Dsus2][D]

(Chorus)
[G]                     [D]                  [C]       [G]         [Em]       [D]
Saviour, He can move the mountains, my God is mighty to save, He is mighty to save.
[G]                  [D]                 [C]           [G]          [Em]          [D]
Forever, author of salvation, He rose and conquered the grave, Jesus conquered the grave.

[C][G][Em][D][Dsus4][D][Dsus2][D]

(Verse 2)
[C]              [G]                       [Em]      [D]           [C]
So take me as You find me, all my fears and failures; fill my life again.
[C]              [G]                   [Em]           [D]     [C]
I give my life to follow, everything I believe in, now I surrender.

[C][G][C][D][Dsus4][D][Dsus2][D]

(Chorus)
[G]                     [D]                  [C]       [G]         [Em]       [D]
Saviour, He can move the mountains, my God is mighty to save, He is mighty to save.
[G]                  [D]                 [C]           [G]          [Em]          [D]
Forever, author of salvation, He rose and conquered the grave, Jesus conquered the 
grave.(x2, then break)

[C][G][D][Dsus4][D][Dsus2][D](x2, then bridge)

(Bridge)
[C]                 [G]                 [D]         [C]           [G]          [D]
Shine your light and let the whole world see. Were singing for the glory of the 
risen King. Jesus (x2)


From here you can bounce between the Bridge and Chorus as the Spirit moves you.

Hope you enjoy, Be Blessed

Psa 108:1&3