Christianism had various definitions over the years. It was originally defined as "the Christian religion" or "the Christian world". In recent years, Christianism (or Christianist) has also been used as a descriptive term of Christian fundamentalists, mostly in the United States, for the ideology of the Christian right

Christian right

Christian right is a term used predominantly in the United States to describe "right-wing" Christian political groups that are characterized by their strong support of socially conservative policies...

, meant as a counterpoint to "Islamism

Islamism

Islamism also , lit., "Political Islam" is set of ideologies holding that Islam is not only a religion but also a political system. Islamism is a controversial term, and definitions of it sometimes vary...

". Writing in 2005, the New York Times language columnist William Safire

William Safire

William Lewis Safire was an American author, columnist, journalist and presidential speechwriter....

 attributed the term (in its modern usage) to conservative

Conservatism

Conservatism is a political and social philosophy that promotes the maintenance of traditional institutions and supports, at the most, minimal and gradual change in society. Some conservatives seek to preserve things as they are, emphasizing stability and continuity, while others oppose modernism...

 blogger Andrew Sullivan

Andrew Sullivan

Andrew Michael Sullivan is an English author, editor, political commentator and blogger. He describes himself as a political conservative. He has focused on American political life....

, who wrote on June 1, 2003:

I have a new term for those on the fringes of the religious right who have used the Gospels to perpetuate their own aspirations for power, control and oppression: Christianists. They are as anathema to true Christians as the Islamists are to true Islam."

The liberal bloggers Tristero and David Neiwert

David Neiwert

David Neiwert is a Seattle-based freelance journalist and blogger. He received the National Press Club Award for Distinguished Online Journalism in 2000 for a domestic terrorism series he produced for MSNBC.com....

 used the term shortly after. Sullivan later expanded on his usage of the term in a Time

Time (magazine)

Time is an American news magazine. A European edition is published from London. Time Europe covers the Middle East, Africa and, since 2003, Latin America. An Asian edition is based in Hong Kong...

magazine column. Uses of the term can be found dating back to the seventeenth century, but these are unrelated to its modern meaning.