Justin Welby has said that new family structures, including same sex unions, are now a reality "whether we agree or not" in a sermon which dismissed the idea of a Victorian golden age of family values as a "myth".
Addressing representatives of the Mothers' Union (MU) from around the world at a special service in Winchester Cathedral to celebrate the organisation's 140th anniversary, Welby praised the MU's aim of "supporting family life" at a time of rapid social change.
However, he said that the "myth" of stable Victorian values was "just that – mythology", the Telegraph reported.
The Archbishop praised Mary Sumner, the rector's wife who in 1876 founded the MU, the Anglican-based group which now has more than four million members in 83 countries.
"Family life in Victorian times was under great pressure, especially in the poorest parts of the country," he said. "Mary Sumner acted out of concern not only for her own family but for a country in a terrible situation in which children were not nurtured, women were at risk, households were not stable and the Church was not doing very much about it other than preaching."
Welby, who recently learned that his alcoholic father was not his biological father, and whose parents divorced when he was young, paid tribute to the importance of family in his own life. "I know from myself that there is nowhere I can take my failures as safely as around the table in the family," he said. "And I know having grown up in a different environment, a different sort of household, what a gift of grace that is."
Welby said that change is "not always bad" but he added that many institutions and churches have been left "living in a culture that they have not yet begun to come to terms with".
He added: "It is not less nor more challenging now to have strong families in the 21st century than it was for Mary Sumner and the need for reliance on God is the same."
Welby argued against same-sex marriage in the House of Lords but by all accounts has embarked on a "journey" on the issue of homosexuality and the Church. Last month, he told the Greenbelt Christian festival that he was "constantly consumed with horror" at the way in which the Church had treated gay people.