The United Reformed Church (URC) has more than 600 active ministers across England, Wales and Scotland.
Many work in churches, but a variety work in other settings that include universities, prisons, the armed forces, hospitals, and other work-based chaplaincies.
The Revd John Mackerness, is a full-time chaplain at Heathrow Airport. More than 75,000 people work there and last year, more than 80 million passengers passed through it. John explains what his ministry entails.