Capo 2
The whole song is just different strumming patterns of C, G, Em, D  

Intro: C G Em D x2

Verse 1:
            C            G              Em       D
One million reasons why, you shouldn't even try.
        C              G                  Em            D     
After all you're just one heart, a single candle in the dark.
               C             G      Em      D     
And there are shadows here, feeding on your fears,
               C            G               Em            D
That you don't have what it takes - who are you to make a change?

Pre-Chorus:
    C   G   Em    D             C       G        Em  D
But oh, oh, don't underestimate the God you follow.

Chorus:
    C               G             Em D
Whatever you do, just don't look back.
   C                   G         Em  D
Oh somebody needs the light you have.
   C                G             Em          
Whatever you do, just don't lose heart.
        D
Keep on pushing back the dark,
C       G                 Em  D
Keep on pushing back the dark.

Verse 2:
         C        G              Em         D
The city on a hill, it should be shining still.
      C               G            Em             D
Every sinner saved by grace, has a purpose, has a place
           C           G         Em        D   
Inside the bigger plan, we might not understand.
          C                 G           Em              D
But if we just keep walking on, we will see the Kingdom come, yeah.

Chorus:
    C               G             Em D
Whatever you do, just don't look back.
   C                   G         Em  D
Oh somebody needs the light you have.
   C                G             Em          
Whatever you do, just don't lose heart.
        D
Keep on pushing back the dark,
C       G                 Em  D
Keep on pushing back the dark.

Bridge: C G Em D
(Let your lights all shine...)
Oh, oh, don't underestimate the God you follow.
He is the light that burns inside your soul,
So keep on shining 'til the whole world knows.

Chorus:
    C               G             Em D
Whatever you do, just don't look back.
   C                   G         Em  D
Oh somebody needs the light you have.
   C                G             Em          
Whatever you do, just don't lose heart.
        D
Keep on pushing back the dark,
C       G                 Em  D
Keep on pushing back the dark.

Chorus:
    C               G             Em D
Whatever you do, just don't look back.
   C                   G         Em  D
Oh somebody needs the light you have.
   C                G             Em          
Whatever you do, just don't lose heart.
        D
Keep on pushing back the dark,
C       G                 Em  D
Keep on pushing back the dark.

Bridge/Outro: C G Em D
(Let your lights all shine)
When you feel like you're too small
(Let your lights all shine)
To do any good at all
(Let your lights all shine)
Like a sunrise through the window
(Let your lights all shine)
Like a symphony crescendo
(Let your lights all shine)
We are waking up again, we are rising from the dead
(Let your lights all shine)
We are shining like the stars, we are pushing back the dark
(Let your lights all shine)
Yeah, we are pushing back, pushing back the dark
(Let your lights all shine)
We are pushing back, we are pushing back, pushing back the dark
(Let your lights all shine)
Just pushing back, we are pushing back, pushing back the dark
(Let your lights all shine)

If you have problems with the chord timings: try playing along with the song on 
youtube. Hope you enjoy playing this song and God bless!