When did Jesus start his ministry?

The short answer

Luke says Jesus was “about thirty years old” when he began to teach. Most historians place that start somewhere around AD 27 to 29. It began after John baptized him in the Jordan River.

What the record says

Luke gives his age:

“Jesus himself, when he began to teach, was about thirty years old” (Luke 3:23)

Luke also dates the start of John’s preaching, which came just before:

“Now in the fifteenth year of the reign of Tiberius Caesar, Pontius Pilate being governor of Judea” (Luke 3:1)

Tiberius became emperor in AD 14, so his fifteenth year falls around AD 28 or 29. Mark tells how it began for Jesus:

“In those days, Jesus came from Nazareth of Galilee, and was baptized by John in the Jordan.” (Mark 1:9)

After that, he taught in the towns of Galilee, many of them along the lake. The exact year and his exact age are not known. “About thirty” is as close as the record gets.

How Son of Man tells it

Son of Man is a novel. It imagines the years the Gospels skip. In the novel he goes by Yeshua, the name his family would have called him. Son of Man ends before the public teaching begins. In chapter fifteen, The Door, Yeshua is twenty-six. His brothers can run the shop now, and he tells his mother at her loom that he is leaving. He walks out on a rainy morning, the first day of the week, and spends more than a year building boats at Capernaum. The story of the years after that continues in Far Country and Narrow Gate.

“I’m going to the lake,” he said. “Tiberias first. Then the other towns.”