Michael Jason Shaw is given the perilous assignment to masquerade as an SS officer in order to infiltrate the German military, stop production of the V-5 rocket, and prevent a Nazi scheme, the Omega Deception, to cripple the United States. Original.
An interesting detail viewpoint from an inside the SS undercover operative in Peenemunde and on a German sub. The author couldn't separate the function of theology, so this became a theological inspiration hung on a pretty intriguing WWII suspense story. I don't remember and didn't research whether stainless steel and sarin gas had been developed for use by late 1942.