It took me a long time to find the answer to this question, but I finally did.

[_The Christ Commission_](https://www.goodreads.com/book/show/435033.The_Christ_Commission), by Og Mandino.

> In front of eight million TV viewers, "The Greatest Mystery Writer in the World" bragged he could prove Christ was actually stolen from the tomb and never really rose from the dead . . . if he were given just one week back in ancient Jerusalem.That night author Matt Lawrence got his wish.A knock-out punch took him right out of this world and landed him in Biblical Judea in 26 A.D., just six years after the execution of Jesus at Golgotha.In relentless pursuit of his investigation, Lawrence walked the same streets Jesus walked, visited the same places . . . and found himself facing the same dangers.Eyewitness reports might lead him to a discovery that would shake the world--but will he live long enough to tell the 30th century that he just solved the greatest mystery of all time?"