 After the outbreak of the Second Sino-Japanese War in August 1937, Cheng offered to re-join his original home, the Covenant Mission group in Central China in spite of his longstanding reluctance to work in foreign-dominated organizations.The Mission Board in California accepted this offer, but the leaders in China rejected it, perhaps because they felt that he would operate autonomously.Cheng then became an evangelist with the China Inland Mission in Sichuan.