Not a historian, but I believe Sojourner Truth is probably one of the names most closely associated with the phrase.

https://en.wikipedia.org/wiki/Sojourner_Truth

Phrases like "I found Jesus" or "y'all need Jesus" have a lot of longevity because they describe a sentiment of experiencing salvation and reconciliation in terms that are understood by a large part of the population.

Instead of "Jesus" you could say "I found my purpose in life" or "I found love" and I think you'd be expressing nearly the same sentiment.