AA is a secular organization, holding as one of its principles that "belief in, or adherence to, a formal creed is not a condition of membership." But the roots of AA were grounded in religion. Co-founder Wilson had a spiritual awakening after he was hospitalized for his drinking in 1934. He and his wife Lois joined the Oxford Group, a nondenominational Christian movement popular in the U.S. and Europe in the early 20th century. The AA tenets of self-examination, acknowledgment of character defects and restitution for harm done to others grew out of Oxford Group teachings. Today, four of the 12 steps in the AA program mention God directly, and the 12th calls for a "spiritual awakening as a result of these steps." As the Oxford Group grew, it suffered from infighting and debate about its purpose. AA, on the other hand, has maintained a stable structure and agenda for most of its existence. "The Oxford Groupers had clearly shown us what to do," Wilson said in 1955. "And just as importantly, we learned from them what not to do."