52% sureLots of sources credit Mother Teresa with this, and they agree with each other. The book or the speech it first came from hasn't turned up yet.
What turned up
Widely documented saying, carried in compilations of her words rather than a dated primary transcript; held at likely on the posthumous-compilation test
Sources checked
en.wikiquote.orgChecked using claude-sonnet-5, 21 August 2026Wikiquote entry carrying the full two-sentence form
Nothing made from these words yet — Storyfaire is where they get made.