Gentry is the son of Donald Gentry and Bernadette Gentry, the younger brother (by five years) of Ralph Gentry and Getrude Gentry, and the husband of Ruth Gentry. He teaches creative writing.

He witnessed his father's miraculous recovery from pancreatic cancer after receiving a kiss from seven-year-old Ayana in 1982; in the same encounter, Ayana touched him as well, and told him: "you be all right." In July of 1983, while Gentry was on sabbatical, he was treated for kidney stones, at which time he was approached by a man who escorted him to a boy in the pediatric ward of Groves of Healing Hospital; Gentry kissed the boy, passing on some of the miraculous healing that Ayana had passed to him. In 1987, the man returned and escorted Gentry to a woman at St. Jude's hospital whom he kissed as well. In mid-December 1997, the man returned for a final time and escorted Gentry to a vehicle crash site where Gentry climbed into the back of an ambulance and kissed one of the victims, giving the man a gold pocket watch that Donald Gentry had given him as a wedding present.