The book has about 10 years of research before being printed. It's by an American author. The book encapsulates some bible stories intertwined with fiction.
It starts with The Man being brought to a morgue and pronounced dead by the female mortician. Shortly afterward the body disappears, and the mortician telephones her husband for advice. The Man is a time traveler - 1 of 12 sent to Earth to help prevent a galactic war from escalating.
During the novel he turns water to wine, evades a cocaine bust by turning cocaine into sugar powder. He is able to exist in several planes at one time - he describes this like many radio waves in a room; they are all there together but do not interfere with each other.
I read this in the 80s, I cannot remember how it ends or who wrote it. I am just trying to find it again.