Keith Hay was described as an 'enthusiastic ‘arm-waver’ who inspired loyalty, as well as confident, ebullient and generous in nature, with a ‘bullet head, rubicund features and wide, toothy smile’. He was a devout Presbyterian, and as Mount Roskill mayor he always started his meetings with a prayer service. He was responsible for Mount Roskill's reputation as Auckland's "
Bible Belt"; in 1988, there were twenty-six churches for the borough's 35,000 inhabitants. In 1969, Hay helped to organise a nationwide New Zealand
Billy Graham Crusade. 1972, he was a principal organiser for the
Marches for Jesus, which involved an estimated 70,000 people. Hay was one of 800,000 New Zealanders to sign a petition opposing the passage of New Zealand's
Homosexual Law Reform Act 1986, and established the
Coalition of Concerned Citizens along with
Sir Peter Tait in 1986. Hay was also devoted to civic and charity work. ==Death and legacy==