This caused controversy due to the thought that Igor had laid the groundwork for the United States rather than the Soviet Union to advance its own aeronautical capabilities. Sikorsky was also deeply religious. He was a Russian Orthodox Christian and the author of two religious and philosophical books, The Message of the Lord's Prayer and The Invisible Encounter. Both of these books summarize his beliefs. He later wrote: “Our concerns pale into insignificance when compared to the eternal value of the human personality – a potential child of God destined to triumph over life, pain and death. No one can take away this sublime meaning of life, and that is all that matters. "(Wikipedia) It was Sikorsky's abiding faith in God and his strong belief in the importance of the individual that helped him overcome the frustrations and failures that marked his career. Mr. Sikorsky liked to say that "the work of 'the individual still remains the spark that drives humanity forward,' and he proved it throughout his life. Even after his retirement in 1957, Mr. Sikorsky continued to work as a technical consultant for Sikorsky and was at his desk the day before dying on October 26, 1972, at the age of 83(