Many Protestants consider marriage to be a sacred institution or "holy ordinance" of God. Roman Catholics and Eastern Orthodox Christians consider marriage a holy sacrament or sacred mystery. However, there have been and are differing attitudes among denominations and individual Christians towards not only the concept of Christian marriage, but also concerning divorce, remarriage, gender roles, family authority (the "headship" of the husband), the legal status of married women, birth control, marriageable age, cousin marriage, marriage of in-laws, interfaith marriage, same-sex marriage, and polygamy, among other topics, so that in the 21st century there cannot be said to be a single, uniform, worldwide view of marriage among all who profess to be Christians.