Twenty eight years ago the political scientist Francis Fukuyama published an essay with the bold title, 'The End of History?' With the passing of the Soviet Union, Fukuyama argued, there were no longer any realistic competitors to the western model of liberal capitalism. It was the final and best form of human government, balancing freedom and equality. This was an idea about ideas – and the idea was that there was no need for any more big ideas. All successful government would simply be a variation on that theme.

In the 1990s it seemed like Fukuyama might be right. New democracies flowered in eastern Europe, and many of the left-leaning parties of the west seemed to concede the argument. No longer did they argue for a different kind of society, just a better version of the one we already had. In the US, the UK, Germany and New Zealand the 'Third Way' was born. Left of centre parties abandoned ideological socialism in favour of a market-plus-social-justice. The structure of society would be left largely untouched, but the less well-off would be looked after by the state funded by wealthier tax-payers. As New Labour doyen Peter Mandelson once said, they became 'intensely relaxed about people getting filthy rich as long as they pay their taxes'.

The problem with the 'end of history' thesis is that nobody told history. 2001 (the attack on the Twin Towers), 2003 (the beginning of the Iraq war), and 2008 (the financial crash) will stand as years where liberal democratic capitalism suffered body blows. Security, global leadership and the financial systems have experienced a great disruption, and it is no surprise that the effects of this continue to spill into domestic politics, including on the level of political ideas.

The 2008 crash in particular created the conditions for a revival in the contest between big ideas. The financial crash, followed immediately by massive state support of the banking sector made a mockery of the rhetoric of laissez-faire capitalism – these great engines of the entrepreneurial economy needed massive public investment to dig them out of a hole of their own making.

The sovereign debt crisis that followed after (where financial institutions stopped lending to governments) created economic and social havoc on countries like Greece, and posed tough questions against the solidarity of European nations. Even in the UK, the state itself has been forced to change its size and scope in order to manage down its deficit – that is, the annual gap between income and spending, before even thinking about existing debt. Whether it has been necessary and effective or not, austerity has certainly undermined the social compact that undergirds British politics.

The ideological picture at the general election feels reassuringly familiar. In the red corner, we have Corbynism – defined at least partly by a rejection of New Labour. Corbyn's Labour does, at least in theory, advocate a different approach to government, taxing the wealthier more aggressively, renationalising key services like rail and mail, and offering big retail policies like the abolition of tuition fees. The mood music against 'neoliberalism' and 'the few' provides an umbrella under which a wide progressive alliance can gather.

In the blue corner, we have Mayism – with her solid conservativism with an aspiration to help the 'just about managing'. On the one hand, the ideological mood music is hard to pick up under the relentless repetition on the words 'strong and stable'. On the other, it is clear that the liberal conservativism of Cameron and Osborne has gone, and here's something new. May's conservatives are not neo-Thatcherites. If anything, they're trying to do what New Labour did, consciously rejecting hard ideological commitments – 'We must reject the ideological templates provided by the socialist left and the libertarian right and instead embrace the mainstream view that recognises the good that government can do... We do not believe in untrammelled free markets. We reject the cult of selfish individualism. We abhor social division, injustice, unfairness and inequality. We see rigid dogma and ideology not just as needless but dangerous.'

The dim prospects in this election for third and fourth placed parties (SNP excepted) are another way in which the country has reverted to the politics of a previous era. UKIP polled 3.9 million votes in 2015 (for one solitary seat), but their powers now are much reduced.

This points to the elephant in the ideological room: Brexit. The politics of Brexit are arguably more important now than the usual ideological positioning between left and right – it has been the main expression in the UK of a much broader political phenomenon of identity based populism, which has emerged in response to challenges of the 2010s. This politics cut across traditional lines. Political parties have to trim their ideological sails to the new wind, while being careful not to alienate important parts of the base.

The author David Goodhart has described Britain as a nation now dominated by two tribes – the 'Anywheres' and 'Somewheres'. Anywheres tend to be relatively wealthy, university educated, mobile, and comfortable with multiculturalism. The Somewheres, in contrast, 'have lost economically with the decline of well-paid jobs for people without qualifications and culturally, too, with the disappearance of a distinct working-class culture and the marginalisation of their views in the public conversation.' Although they lack cultural profile, the Somewheres are far more numerous (perhaps half the population) than the Anywheres (perhaps a quarter of the population).

One way to think about the general election is as a battle for the 'Somewheres'. Can Labour attract back the Somewheres who voted UKIP in 2015? Can it make a clear argument on immigration? How many traditionally Labour-voting Somewheres will vote Conservative, on the basis Brexit means Brexit? Have the Conservatives done enough to convince those Somewheres that the 'nasty party' are tuned into the needs of the just about managing. Can Labour appeal to Somewheres and Anywheres at the same time? Liberal Democrats and the Green Party are competing for Anywheres along with Labour – who can break through? Scottish Nationalists provide an interesting case study in how to root yourself in multiple ideologies – they attract both traditional nationalists Somewheres and progressive Anywheres. Pre-Brexit, this took nearly every constituency in Scotland.

So what are the main lessons? First, ideas aren't dead and gone from politics – they're as important as ever. Second, politicians do not have the luxury of being philosophers. They have to fit their thinking into the wider political context. Not only do they have to hold their ideology lightly but they have to make it work in their favour, using it to speak to the big political questions of the day. Third, politics is about power, and many politicians and political parties don't necessarily set out their ideological positions, in fact often they deliberately hide them. Christians need to be aware of the ideas at play under the surface of party politics. They're like underwater currents, which exert an invisible but powerful influence! To understand politics, we need to understand what these ideas are and how they pull in different directions.

Christians themselves don't stand apart from these powerful political undercurrents, but they are warned that our own thinking should not be defined by them, not conforming to the 'pattern of this world'. In the week between now and the election, many Christians will make a mistake of claiming that their own political ideology is self-evidently the 'Biblical' one. They can't all be right. They can be, and they are, all wrong.

Paul Bickley is the Director of Political Programme at Theos. He is the author of 'Building Jerusalem? Christianity and the Labour Party (2010)' and a number of Theos reports. Find him on Twitter @mrbickley