The biblical attitude to state-based welfare provision in Britain has been strangely similar to its attitude to democracy: the raw materials were there from the earliest times but so was a distinctly critical attitude.

A little over 100 years ago, a Charities Commission report commented that "the latter half of the 19th century will stand second in respect of the greatness and variety of charities created within its duration, to no other half-century since the Reformation". The vast majority of those charities were founded, funded and operated by Christians who were simply following biblical precepts. "For I was hungry and you gave me food, I was thirsty and you gave me drink, I was a stranger and you took me in, Christ said in Matthew 25. "Inasmuch as you did it to one of the least of these my brethren, you did it to me."

That there was a biblical imperative to feed, clothe, heal and help was never in doubt. The question was how.

In the earlier 19th century, in what historian Boyd Hilton called the Age of Atonement, there was a powerful Christian opposition to state-based welfare provision. It was wrong for government to interfere in the market and social affairs for fear of upsetting God's sanctified, if harsh, moral order. Charity was mandatory, but it was also personal.

This changed, slowly, as the 19th century progressed, and an age of atonement gave way to an age of incarnation in which the fraternal suffering of the Son was emphasised over the severe judgement of the Father. By the end of the century Archbishop Frederick Temple, addressing a deputation of trades' societies, cautiously affirmed a scheme proposed by Charles Booth that the state should pay a pension of five shillings a week to everyone over the age of 65. That would have been unthinkable for any archbishop earlier in the century.

The battle between those who sought state-based welfare solutions and more community ones raged in the interwar period, but the tide of centralised planning won the day, in part because two friends, contemporaries and Christian socialists, RH Tawney and William Temple, threw their weight behind the idea. Temple even coined the term "welfare state", although he did so in specific contrast to the "power state" of contemporary totalitarianism, rather than in direct anticipation, still less delineation, of the Beveridge plan.

In the immediate postwar period, the Attlee settlement became received Christian wisdom. "Christians should welcome [it as] the embodiment of the principle, 'Bear ye one another's burdens and so fulfil the law of Christ'," wrote Cyril Garbett, Archbishop of York. "In bringing relief to the poor, giving food to the hungry, finding work for the unemployed, caring for the children and the aged, and providing healing for the sick it is carrying out the word of Christ."

The critical voice was never far below the surface, however, and the arrival of the self-consciously Christian Margaret Thatcher gave it a powerful articulation. Britain's problems, she insisted, were as much moral as they were economic. "The economy had gone wrong," she later wrote, "because something else had gone wrong spiritually and philosophically."

Thatcher, brought up in a devout Methodist home, was a spiritual descendent of the evangelicals who shaped the Age of Atonement. But we, in turn, as Andrew Marr remarked in his History of Modern Britain, are all Thatcher's children, and in that respect the current reformation of welfare provision in the UK is another chapter in the tussle between atonement and incarnation.

This is not to claim, as some do, that the "big society" or Iain Duncan Smith's welfare reforms are cynical attempts to obliterate the state and impale the vulnerable on the harsh justice of the market. They are not.

Rather, it is to say that our attitudes to welfare policy are invariably tied up with our differing conceptions of justice and our understanding of the human person. And because human persons are uniquely free, moral, meaning-seeking animals, that means that our attitudes are, at root, however reluctantly, theological.

This article first appeared in the Guardian.