When my mother sang it, it was "Darky Sunday School", which is, of course, offensive, Darky being a term for African Americans. I've also heard it sung as Mormon Sunday School. I wrote my own version of the chorus:
Young folks old folks everybody come
Come into the TV room and make yourself to home.
We'll watch the televangelist, he's on on Channel Four.
And you'll hear some Bible stories like you never heard before.

This might offend televangelists. But I really don't care.