He was best known for his longstanding and respected work with the media, most notably the wry and gentle sense of humour on "Thought for the Day" on BBC Radio 4's Today programme. He was also widely respected in the UK as a journalist, cook and author.
Born in the East End of London, Blue was the son of a master tailor.
Blue read History at Balliol College, Oxford and Semitics at the University of London before being ordained as a rabbi in 1960. He spent time in the Army but was discharged after a nervous breakdown brought on by anxiety over his homosexuality.
He lost his faith at the age of five after petitionary prayer failed to remove Hitler and Oswald Mosley, he then turned to the Marxism of his uncle. Blue regained his faith while at the University of Oxford, when he found some resolution to severe personal conflicts regarding his sexuality at a Quaker meeting. He also found Victor Gollancz's A Year of Grace helpful during this time, and finally became one of the first two students at Leo Baeck College for training rabbis in 1956.
Between 1960 and 1963, Blue was the minister of the Settlement Synagogue and Middlesex New Synagogue. He then became the European Director of the World Union for Progressive Judaism. In 1967, he began a long-term engagement as lecturer at Leo Baeck College in London.
Blue was the first British rabbi publicly to affirm his homosexual orientation and published Godly and Gay in 1981. He has been openly homosexual since the 1960s and has had three male live-in lovers. He met his most recent partner, Jim, in 1981 through a personal advertisement in Gay Times. However, his memoirs reveal that he considered marrying Joanna Hughes, a student whom he met whilst they were both students at Oxford in 1950.