Winter grew up in the Los Angeles area. His father, Hugo, was a self-trained engineer who ended up leading a division of the L.A. planning department with 1,200 engineers under his leadership and was instrumental in the development of the greater L.A. Freeway system. When World War II broke out, Ralph was too young to enlist, so he studied for just two and a half years at Caltech and earned his B.S. degree, in order to join the U.S. Navy's pilot training program. Before he finished that training, the war ended and he was discharged, but his service in the Navy helped pay for his further education. He then went on to earn his MA at Columbia University, and PhD at Cornell University, and then a B.Div. at Princeton Theological Seminary. With childhood friend Dan Fuller (son of revival preacher Charles E. Fuller), he also studied at Fuller Theological Seminary in Pasadena, Calif., the first semester the school was open in 1947. He would later teach there.