This week has seen two public institutions facing serious accusations of corruption. Firstly there were the claims by former undercover police officer Peter Francis that he was ordered to dig up 'dirt' on the family of the murdered teenager Stephen Lawrence.

The allegations that police were deployed secretly in an attempt to smear the victims of such a serious crime have been described by the Lawrence's lawyer, Michael Mansfield QC, as "institutionalised deceit".

Secondly, scandal has also hit the Care Quality Commission (CQC), the body responsible for inspecting hospitals and care homes. They were accused of covering up a report, which exposed their failure to properly investigate the deaths of 16 babies and two mothers due to neglect in a hospital in Cumbria. The author of the report was told to destroy his findings to protect CQC's reputation. It has led to CQC's chairman, David Prior, saying that the commission was "not fit for purpose".

Like the BBC's Jimmy Savile scandal, these are further examples of the damage caused when cultures of corruption and cover-up become embedded within institutions established for the public good.

So what does a Christian response look like?

Firstly, these scandals are a powerful illustration of one of the least popular of all theological topics: sin. Sin is perceived by many as a very judgmental concept because it is so often used only in relation to personal moral, often sexual, issues.

But in these cases we see the impact of sin, which is beyond just the realm of the individual. Of course, the decision to smear the victim of a crime or the suppression of a critical report is wrong, but in these examples the wrongdoing has been compounded, maintained and concealed through an institution. Sin is manifested in corporate failure.

The Archbishop of Canterbury Justin Welby wrote a booklet called Can Companies Sin? (Grove 1992) reflecting on his experiences working in the oil industry. The answer he finds to his own question is a resounding 'yes'. Despite their complexity, companies and institutions have moral responsibilities just as individuals do. Despite our fondness for a scapegoat who can be sacked to carry the can, few corporate scandals are any one person's fault. Often it comes down to the "negligence, weakness and deliberate fault" of many.

This is the sin-sickness of the world, the key underlying cause of all injustice. Rather than being used as a way of pointing the finger of judgment at others, a full and radical understanding of sin is the best way of understanding why the world is in the mess it is.

Through the presence of Judas in Jesus's community, the multiple failures of Peter and the disputes of Paul with his colleagues, the Bible is reassuringly clear about the presence of sin in the Church. Church history ever since has been a rich story of both the divine and the dusty. This can give us an earthy realism about the self-serving tendency inherent within all institutions.

This realism helps us avoid twin dangers of cynicism and naivety. We should reject the easy commentary of the cynics who simply deride all public bodies as hopelessly corrupt. They are wrong – strong public institutions are fundamental to any country and many good people are faithfully working within them. But we should also reject the naivety that leaps to defend public institutions at all costs. We should be wary of shifting the blame onto one or two 'bad apples' while ignoring the corporate nature of problems.

And there is a role for all of us. Whether at work, in our communities or our churches, we can commit to speak the truth about issues that need exposing and addressing. When we do this, we become those who bring light to shine in the darkness of a sin-sick world. We should not be superior but humble, for we are not free of sin, but simply follow the one who is. The one who said: "You shall know the truth and the truth will set you free."

Jon Kuhrt is executive director of social work at the West London Mission and blogs at www.resistanceandrenewal.net