Evangelist Billy Graham was admitted to Mission Hospital in Asheville, N.C., today as doctors evaluate treatment for his lungs.

Graham’s personal physician, Lucian Rice, said the 93-year-old is in stable condition.

Graham was seen “alert, smiling and waving at hospital staff,” according to a statement from his family.

A discharge date has not been determined.

He is currently being tested for possible pneumonia, according to hospital officials.

In May, he was treated for pneumonia.

“Mr. Graham is looking forward to returning home to spend the upcoming Christmas holidays with his family,” read a statement released by Graham’s family and staff.

He recently authored what The Associated Press said was his 30th book, “Nearing Home.” The book on aging was published last month.

Graham is known for bringing evangelical Christianity into the mainstream and counseling U.S. presidents from Harry Truman to Barack Obama.