The security guard found and removed a piece of tape that was keeping a door from clicking shut. Later, when he checked the door, he found it had been taped again. He called the police, who arrived and arrested five burglars.

Working at the Watergate building in Washington, D.C., the headquarters of a major political party in the US, the young guard had just uncovered the biggest political scandal of his lifetime simply by taking his job seriously—and doing it well.

Nehemiah began rebuilding the wall around Jerusalem—a task he took very seriously. Toward the end of the project, neighboring rivals asked…