Throughout his life, William Booth sought to minister to the least, the last, and the lost. Booth, together with his wife Catherine, founded and organized the world-wide mission that is still known as The Salvation Army.

Booth's focus on the poor and marginalized comes directly from his theological convictions and his relationship with the Methodist movement in Great Britain, particularly his understanding of John Wesley's doctrine of sanctification and emphasis on social activism. This grounding was the matrix from which Booth transformed his world.