After studying at St. John's University in Queens for two years, he enlisted in the United States Marine Corps and fought in the Korean War.
In the late 1960s, Manning joined the Little Brothers of Jesus of Charles de Foucauld, a religious institute committed to an uncloistered, contemplative life among the poor.
Manning transported water via donkey, worked as a mason's assistant and a dishwasher in France, was imprisoned (by choice) in Switzerland, and spent six months in a remote cave in the Zaragoza desert.
[8] Mannings' writings led to a more public ministry, and he was often asked to speak and to lead spiritual retreats.
[9] Manning was often public about his faults, noting at his high school reunion that during his life he had been "promiscuous, a liar, envious of the gifts of others, insufferably arrogant, a people-pleaser and a braggart", but he shared how, "By sheer undeserved grace, I've been able to abandon myself in unshaken trust to the compassion and mercy of Jesus Christ.