Thoughts, prayers and tributes are being offered following the death of Yorkshire Labour MP Jo Cox after an attack in her constituency. At 41 years old, she had 30 or 40 years of public service left to offer when she attended a constituency surgery yesterday. We can barely imagine the world that her family is waking up to today.

Speculating about causes isn't helpful. All we can do is pray for her family, and for the police and justice system to act swiftly and decisively.

What we can reflect on is how fortunate we are in the UK for this to be such a rare occurrence. We can also reflect on how blessed we are to live in a culture where violence is comparatively rare, where politicians are still approachable and where we have robust policing, judicial and medical systems to make us as safe, secure and healthy as we are.

During the run-up to the EU referendum, I have frequently despaired at the tone of the debate and the way both sides of the campaign have behaved. It's the latest in a long line of things which have drawn attention to the cynical, sometimes dirty nature of politics.

Yet today, I'm reminded of the overwhelming good that exists in our political system. To live in a democracy where we get the chance to vote both in the EU referendum and for our local and national representatives is a privilege known by very few of our fellow humans throughout the history of the world. Our democracy is far from perfect – there is much work to be done – but today isn't the day to pick holes in the system. It's a day to be grateful for our relative freedom and ability to control our own political destiny.

It's also a day to be incredibly grateful to Jo Cox and the many thousands of faithful, hard working and conscientious MPs, councilors, members of the devolved assemblies, police commissioners, mayors and other elected officials across the country. While we witness the half hour of political theatre during Prime Minister's Questions, what we don't always witness is the amount of sheer hard work, much of it unglamorous, which is done by our MPs and others, and the way they often work together across party lines.

Being an MP is incredibly tough. Long days away from the family, constant intrusions from the media, the pressure of making very hard decisions. Many of them could make more money outside of politics but they choose to serve, and to try and seek the common good. They may not always make the right decisions, but do the very best they can. Our democracy simply wouldn't work if good people didn't take on this vital role.

Virtually all MPs carry out regular advice surgeries in which the people they represent can come and speak with them face to face about issues which are concerning them. It may be the big global issues such as climate change and the refugee crisis, or it may be a local problem with a park, a school or a hospital.

Christian MP Stephen Timms is among this hardworking group. I've seen him up close on a number of occasions going above and beyond the call of duty. When he was stabbed during a surgery in Beckton in east London, he made a full recovery. Despite the fear that would have been only natural, he and other MPs continued to meet constituents and to do their jobs despite the obvious risk.

It would have been easy to hide behind the impregnable security of the Palace of Westminster, especially seeing as Timms has one of the safest seats in the country. Instead he carried on fighting hard for his constituents – even those with whom he disagreed, perhaps profoundly.

Jo Cox worked in war zones for development charity Oxfam. She exemplified a commitment to service, a desire for justice and a passion for making the world a better place. These traits are shared by many of our public servants. We must remember this – especially those of us who are prone to become cynical about the political process. Our approach to policies, economics and social issues may differ, but we have to recognise the huge sacrifices our politicians make in the cause of the common good. Yesterday Jo Cox made the ultimate sacrifice. We are all in her debt.

Follow Andy Walton on Twitter @waltonandy