The Ruling Class (1972) on Netflix

Following Lord Ralph Gurney's accidental death, his son Jack Gurney inherits his estate including his title, the Earl of Gurney. Jack has been away for seven years, having no contact with his extended family during that time. He believes he was at a monastery. In reality, he was in a psychiatric hospital as a voluntary patient - voluntary at his father's request - as, as a paranoid schizophrenic, he believes that he is Jesus Christ in leading a movement for eternal love, the latter issue of all men being equal which may be more problematic for his family who are part of the so-called ruling class than his belief of being God. In his own words, when he prays to God, he hears himself. Any of life's problems he places inside his virtual "galvanized pressure cooker". His paternal uncle and his family are most concerned about Jack taking over the peerage and the vast estate, and what that will do to the historic Gurney name. Competing interests in the family work toward two opposing possible options to deal with the situation: to have anyone that they can manipulate with a Gurney name take over, at which time they can recommit him for good; or to see if his long standing psychiatrist at the hospital, Dr. Herder, can cure him by getting him to face reality. Jack may, however, throw them all for a loop.