"Adam and Steve" is a phrase that originated from a conservative Christian slogan "God made Adam and Eve, not Adam and Steve", intended to concisely summarize Judeo-Christian Bible-based arguments against gay sexual practices or homosexuality. Among other things, it implies that the natural way of life for humanity is illustrated by the Biblical account of the creation of human beings as a male-female pair.
The phrase appeared, on a protest sign, as early as 1977, as mentioned in a New York Times news service report about a November 19 rally in Houston that year. Two years later, Jerry Falwell gave the phrase wider circulation in a Christianity Today report of a press conference he had given. The phrase later acquired a certain notoriety, and, when used to name a pair of characters in a work of fiction, helps to identify them as members of a homosexual pair (Paul Rudnick's play The Most Fabulous Story Ever Told, the 2005 film Adam & Steve and other works). The phrase was used by the Democratic Unionist Party MP David Simpson, an opponent of same-sex marriage, during the British House of Commons' debate on same-sex marriage, although a slip of the tongue originally saying "in the Garden of Eden, it was Adam and Steve" initially caused laughter in the chamber.