Scotland is lucky that it is not a majority-Muslim nation today, or it would be in danger of being put under unfeasibly large house arrest by Theresa May.

The Home Secretary announced on Wednesday that she would be bringing in tough new anti-extremism powers that would target those who sought to "divide our society". As a nation that recently voted quite convincingly for a party that seeks to divide Britain comprehensively, I have to assume that all of Scotland shifted uneasily at the breakfast table while listening to her remarks.

Speaking on the Today Programme on Radio 4, May said tough new measures would be brought in to combat those who were "trying to be divisive" and to undermine the rather vague concept of "British values".

Much has been made of the impossibility of defining, particularly by diktat from on high, what British values might actually be, and certainly there is much to worry about when a society decides what ideas do and don't belong and links them to belonging in the country. After all, who is to decide what constitutes values that are truly British? Theresa May came up with "the rule of law" (which I suspect many other nations would dispute was essentially British); "freedom" (take that, America) and "democracy" – which is an odd value to pick as essentially British considering we arguably only properly embraced it about 60 years after the French and 80 years after the Americans (them again!).

But will Theresa May's new measures be targeting those who think we should return to a time when monarchs wielded real power, or those who think democracy is pointless (I'm looking at you, pre-epiphany Russell Brand)? Of course not.

It will also not be targeting those who hold strong views on either side of issues that actually divide our society – nor those who are actively promoting ideas that cause division. I'm thinking of anyone strongly for or against gay marriage. Or nuclear weapons. Or austerity, UKIP, 'the one per cent' or the European Union. Because while these subjects do divide people, they are not what Theresa May or this government mean when they talk about division. They mean Muslims. Muslims who have their doubts about democracy. Muslims who have views on gay people, women and our foreign policy.

Cartoonists who depict bankers as obese kittens, teenagers in Che Guevara t-shirts and Christians who still believe Jesus is the only way to God are all more or less safe from the law, for now. But if you believe that we are on the wrong side of a war (and being allowed to believe and express that is fairly important if we are to hold our politicians to account and preserve any hope of a moral compass for our nation), you had better be a white, secular footballer and not a Muslim cleric.

But even if May's proposals were not so very obviously aimed at just certain types of divisiveness, expressed by certain types of people (if you think I'm exaggerating, ask yourself why Oxford and Cambridge have special exception from the ban on teaching 'extremist' ideas), they should still frighten you. The government's plans for 'disruption orders', banning groups and denying access of certain people to the right to be heard in broadcast media do not focus on those who use hate speech or incite others to violence. There are already laws against that. People potentially targeted by these laws could include many nonviolent activists who the government deems a "threat to the functioning of democracy".

Another of the apparently British values May identified on Wednesday was "tolerance" – a concept she appealed to several times, suggesting that the extremists she was targeting were a threat to that particular value. But tolerance, if it is to mean anything at all, must mean tolerance of those we disagree with. After all, if we agreed with them, we wouldn't need to tolerate them, because we'd... well... agree.

Tolerance and free speech – core values of a truly democratic society today – only have meaning if they protect speech which is unpopular, speech that might seem threatening, speech that could be divisive.

Without the freedom to ask fundamental questions and promote ideas that may seem revolutionary and scary to some, we would still live in a country where slaves were bought and sold and where Socialism never had a chance to take hold and give us the NHS. Without the right to hold what many might see as wrong opinions, what government might say are bad opinions and what some might call crazy opinions – and to express them – we are not really free. Who, after all, gets to decide which opinions are allowed? The government? MI5? Popular vote? Do you trust any of these not to exclude some cherished aspect of your identity or beliefs?

Christians, who believe many things that the world sees as crazy, wrong and even bad, should be deeply afraid of a law that would decide for us what ideas we are allowed to hold or express.

Jesus said that he came to bring a sword and that he would be the reason for division even within families (Matthew 10:34-36). We may not agree with the people Theresa May is targeting right now, but if we truly believe in freedom, tolerance and democracy we should protect their right to their own thoughts and opinions.

After all, divisiveness is inherent in the Narrow Way – and is, I think, a truly British value.

Jonathan Langley is a freelance writer and works for a Christian mission and development agency.