I may never march in the infantry,
Ride in the calvary, shoot the artillary,
I may never zoom  o'er the enemy,
But I'm in the Lord's Army (yes sir!)

I'm in the Lord's Army (yes sir!)
I'm in the Lord's Army (yes sir!)

(repeat)

This song has hand/body motions (for children, give them a lot of room): 
"march in the infantry" - march in place
"ride in the calvary" - pretend to be riding a horse
"shoot the artillary" - use hands to motion a rocket leaving a plane
"zoom o'er the enemy" - hold out arms and move around like a plane
"yes sir!" - salute while saying it