Like the canaries miners once carried underground as an early warning sign for dangerous gases, the resignation of Frank Field from the Labour whip is an urgent alarm call.

It's a siren sounding a top-volume wake-up call for all who care about intelligent politics in the UK – and Christians in particular should be sitting up and taking notice.

That's because he has consistently supported causes which Christians care (or should care) about. He is the one who set up the All-Party Parliamentary Group on Hunger and Food Poverty. A keen environmentalist, he established the charity Cool Earth, which works to protect rainforests. He is also an eloquent exponent of the rights of unborn children, campaigning for a reduction in the timespan within pregnancies during which abortions can be performed.

A practising Christian and Anglican, he has been a member of the Church of England's General Synod. Last year, he received the Langton Award for Community Service from the Archbishop of Canterbury 'for sustained and outstanding commitment to social welfare'.

He has not been afraid to think independently, forming a surprising friendship with Lady Thatcher. And on Brexit, rather than adopting a stereotypical off-the-shelf view for one side or the other, he agonised about the issue before coming down – reluctantly – on the side of leaving the EU. As chair of the all-party Work and Pensions Committee, he has spoken out against the new Universal Credit benefit, arguing it has forced many people into debt and dependency on food banks.

So when a politician with such Christian principles and intelligent independent-mindedness quits one of Britain's two biggest political groupings everyone should be worried. In an age where many people find it difficult to name politicians they genuinely admire, Frank Field has been one person who – rightly – can command such respect.

His critique of the current state of the Labour Party is compelling. In his resignation letter, he writes: 'It saddens me to say that we are increasingly seen as a racist party. This issue alone compels me to resign the whip.' He also speaks of a culture of 'intolerance, nastiness and intimidation' in his own local party and beyond. For example, that local party voted to refuse diversity training from the Jewish Labour Movement because on the grounds of alleged links to Israel and (bizarrely) Islamic State – connections described by the left-wing New Statesman magazine as 'entirely non-existent'.

Many of us have probably lost track of all the details of Labour's long-running antisemitism battles. Most of us will, however, probably have thought it disturbing that the party seems to have had a problem with adopting an internationally-recognised and widely-used definition of what antisemitism actually is.

And quite a few of us will also have instinctively felt that Jeremy Corbyn's plea about being present at – but not taking part in – wreath-laying at the graves of terrorists was distastefully reminiscent of Bill Clinton's infamous attempt to sidestep charges of taking drugs by admitting he 'smoked weed but didn't inhale'.

The Bible is pretty hot on social justice. As the prophet Amos put it in some well-known words, 'let justice roll on like a river, righteousness like a never-failing stream'. Frank Field is an MP who has embodied those words not only in his declared faith but in his actions. While it's absolutely possible for Christians to be members of many political parties with integrity, if one such as him no longer feels able to be part of the UK's main left-wing grouping, then it is in deep trouble.

Interestingly, in speaking about his future, Field has referred to his Christian beliefs by declaring that 'providence willing' he would like to serve his voters for another term – presumably as an independent MP. Most observers reckon he is likely to see off any challenge from an 'official' Labour candidate easily, and thus be re-elected.

So let's raise a glass to this Christian-principled and independent-minded MP who has fought so hard for many causes which are aligned with a Christ-centred worldview. He has done that with integrity, creativity and thoughtfulness.

And let's pray that more MPs of all parties might demonstrate similar courage, conviction and the determination to 'walk the walk' as well as 'talk the talk' of faith in action.

Our country desperately needs such people more than ever.

David Baker is a former daily newspaper journalist now working as an Anglican minister in Sussex, England. Find him on Twitter @Baker_David_A