Guinness was born in 1914 in London to a broken family. He never knew his father and grew up in poverty. Though he was confirmed an Anglican at 16, he was unsure of what he really believed about religion. As a young adult, he dabbled in Presbyterianism, atheism, Marxism, Buddhism, and even attended a few Quaker meetings, according to biographers.
While Guinness was rehearsing for a performance of "Hamlet," an Anglican priest approached him, explained that he was blessing himself incorrectly, and showed him the correct way. Something about the encounter had a spiritual impact on him, and rekindled his interest in Anglicanism.
He was drawn further into the Anglican faith in the turmoil of World War II, but it wasn't until 1954 when he was 40 years old that he had another experience that would open him to considering Catholicism.