I listened to the song, and this is what I believe to be the correct way of playing it.- 
This without a capo, unlike the capo 5 versions i've seen elsewhere.

Chorus:

Em                   C      D      Em
Go make a dff'rence, we can make a diff'rence

G                           Bm7
Go make a diff'rence in the world

Em                   C      D      Em
Go make a diff'rence we can make a diff'rence

C         D                 Em
Go make a diff'rence in the world

First Verse:

Em                                      C       D      Em
We are the salt in the earth, called to let the people see

    G                      Bm7
The love of God in you and me

           Em                            C       D      Em
We are the light of the world, not to be hidden, but be seen

C         D                 Em
Go make a diff'rence in the world


----Chorus----

Second Verse:

Em                                   C      D        Em
We are the hands of Christ, reaching out to those in need

    G                      Bm7
The face of God for all to see

           Em                 C       D        Em
We are the spirit of hope, we are the voice of peace

C   D   Em