In 1904 Chadwick began lecturing weekly at Cliff College, a Methodist lay training centre, commuting from Leeds. In 1907, he was appointed to a faculty position as a biblical and theological tutor. Although he was doing mission work in the South Yorkshire coal fields when the Principal of Cliff died in 1912, he immediately returned to the school and was formally appointed principal in 1913, remaining in that post for the rest of his career.
Famed outdoor evangelist Leonard Ravenhill was educated at Cliff College during Chadwick's tenure.
At Cliff, Chadwick wrote
The Way to Pentecost, which went to print as he was dying in 1932. He also wrote
The Call to Christian Perfection. Chadwick's works have been reprinted often since his death, and continue to be reprinted in new editions under various titles for modern study.
The Way to Pentecost contains this popular quote:
The soul's safety is in its heat. Truth without enthusiasm, morality without emotion, ritual without soul, make for a Church without power. Destitute of the Fire of God, nothing else counts; possessing Fire, nothing else matters.
Another of his most widely published quotes is:
The one concern of the devil is to keep Christians from praying. He fears nothing from prayerless studies, prayerless work, and prayerless religion. He laughs at our toil, mocks at our wisdom, but trembles when we pray.