"Jesus was a teacher and miracle worker who spent nearly all of his brief ministry in the tiny and obscure province of Galilee, often preaching to outdoor gatherings. A few listeners took up his invitation to follow him, and a dozen or so became his devoted disciples, but when he was executed by the Romans his followers probably numbered no more than several hundred.
“How was it possible for this obscure Jewish sect to become the largest religion in the world?”
—Rodney Stark, The Triumph of Christianity
The answer to that question is the Book of Acts.