Allmusic.com lists a song called I'M GOING TO LIVE THE LIFE I SING ABOUT IN MY SONG, attributed to Rev. Thomas A. Dorsey. It was recorded by Mahalia Jackson and several others. I found these lyrics at http://www.geocities.com/Heartland/Plains/8065/life.html:

I'm gonna live the life I sing about in my song.
I'm gonna stand for right, always shun the wrong.
If I'm in a crowd, if I'm alone,
In the street, or in my home,
I'm gonna live the life I sing about in my song.

Every day, everywhere, on that busy thoroughfare,
Folks may watch me, some may spot me,
Say I'm foolish, but I don't care.
I can't go to church and shout all day Sunday,
Go out and get drunk and raise sin on the Monday,
I'm gonna live the life I sing about in my song.

Not for gold nor for fame, but the love of Jesus' name.
I must always walk the straight and narrow way.
Jesus promised me, one of these days,
He's gonna give me a crown of life.
Yes, I've got to live the life I sing about in my song.