Cennick had planned a career as a surveyor, but after meeting the Wesleys, he joined them in their work. In 1840, he became a teacher at Kingswood, England, on the recommendation of John Wesley. Later, he joined the Moravians. He spent much of his time preaching in Germany. Cennick’s works include:

• Sacred Hymns, for the Children of God in the Days of Their Pilgrimage, 1741
• Sacred Hymns for the Use of Religious Societies, 1743
• A Collection of Sacred Hymns, 1749
• Hymns to the Honour of Jesus Christ, Composed for Such Little Children as Desire to Be Saved, 1754

Additional works appeared posthumously in J. Swertner’s Moravian Hymn Book, 1789.