From Wikipedia:
Dr. John F. MacArthur, Jr. (born 1939) is an American evangelical writer and minister, most noted for his radio program entitled Grace to You. He is currently serving as Pastor-Teacher of Grace Community Church in Sun Valley, California, and as President of The Master's College (and the related Master's Seminary) in Santa Clarita, California.
He has also written over 75 books, the most popular being "The MacArthur Study Bible", which has sold over 500,000 copies.