From: I dMb I 
*------------------------------------*
   G A Dm
||-3-5-7-||
||-3-5-7-||

G,A,Dm,Dm

Bridge ("When Jesus Christ was nailed to his tree"):

A,Dm,G,A

On the chorus and bridge, for each chord, you want to strum down, then get

                  A                 D
E-----------------0-----------------2----------
B-----------------2-----------------3----------