Game of Thrones season five was unleashed last week. The hype surrounding the beginning of a new series of a big TV show has replaced the excitement that used to accompany the release of a huge blockbuster film. Whether it be House of Cards, Mad Men, or 'Thrones' (as its devotees affectionately know it), the start of a new season is now one of Western culture's premier events – far outstripping the release of all but the biggest pop records.

But what is the overarching message which goes along with this cultural impact? What's one of the big themes uniting many of the biggest and best TV series of the last decade? Well, forgive me for sounding a little preachy while discussing 21st-century cultural phenomena, but I think the answer is... sin.

One of the great architects of the Reformation, Martin Luther, described the state of sin as "[being] so deeply curved in on itself that it not only bends the best gifts of God towards itself and enjoys them... but it also fails to realise that it so wickedly, curvedly, and viciously seeks all things, even God, for its own sake." If this is true (and there are as many definitions of sin as there are theologians) then it explains what's at the heart of much contemporary TV.

In the world of Westeros and beyond the overarching motivation for the actions of the protagonists, is a lust for power. All the violence, war and political intrigue is a result of that lust – one of the seven deadly sins. In the quote that gives the programme its name, Cersei Lannister explains that the carnage and devastation being wrought by various armies isn't a fight over resources or even primarily about territorial supremacy. She says, "When you play the game of thrones you win or you die. There is no middle ground."

Breaking Bad is another show with sin at its heart. In this instance the whole narrative arc is predicated on a small piece of wrongdoing that leads to a descent into a series of cold-blooded murders. We watch as suburban chemistry teacher Walter White's pride means he refuses to ask friends to pay for cancer treatment, so he becomes a small time drug manufacturer. But, as in many classic morality tales back through Shakespeare and beyond, the 'small sin' of pride leads to lies, violence and death. In Season Five, far into the destructive cycle of sin, White says, "If you believe that there's a hell... we're already pretty much going there, right? But I'm not going to lie down until I get there."

In Homeland we see the consequences of sin passed on. The results of immoral, sinful actions on a national level – ham-fisted imperialist American policies in the Middle East – begin to break apart lives and families back home in the US. Despite its laughable depiction of Sunni-Shia relations, what Homeland gets right is the way in which sin has consequences that can't be contained within the individual. St Paul knows this well when he says, "the wages of sin is death" (Romans 6:23). The Book of Common Prayer puts it like this: "We acknowledge and bewail our manifold sins and wickedness, which we from time to time most grievously have committed, by thought, word, and deed, against thy divine Majesty, provoking most justly thy wrath and indignation against us."

The way in which many of these series show the spiraling consequences of sin is perfectly captured by the contemporary Christian author Philip Yancey. In his classic book, What's So Amazing About Grace? he discusses the way in which the consequences of sin play out from generation to generation. He calls it the "cycle of un-grace". A perfect example would be the corporate sin of the Dutch Reformed Church in South Africa. Its sin of supporting the Apartheid regime had consequences for generations – some of which of course remain, despite Desmond Tutu's best efforts at reconciliation.

In season four of Game of Thrones, one of the story's most intriguing characters, Daenerys Targaryen, sets out what we might call her philosophy, or even her theology. When told that sometimes it is better to answer injustice with mercy – thus breaking the cycle of 'ungrace' – she responds, "I will answer injustice with justice." Which in this case means the crucifixion of more than 100 people.

House of Cards shows us a very different kind of protagonist from Walter White. Kevin Spacey's superbly observed Frank Underwood doesn't descend into sin like White. Instead he's presented from the very beginning of the programme as a character consumed by self-interest – the very personification of Luther's definition of sin. For him, no amount of lying, cheating or killing is too much to prevent him getting to the top. He's avaricious and then some.

You may rightly ask how good any of these programmes would be without the sin which predicates most of their plotlines. And aren't they just reflecting the experience of real life, dramatised for the box-set generation? Well, precisely. Art has been portraying sin and its consequences for thousands of years. But often a sense of redemption has been offered.

In the Christian worldview that redemption comes through Jesus' death and resurrection, something allegorised in the Narnia books, for example. What's remarkable about the current slew of programmes is how little redemption is on offer. Sin is the cause of great despair and a cycle of violence, but in very few of these shows do we get a story of redemption.

Even 20 years ago the big TV shows weren't dealing with these kind of issues so profoundly. In the X-Files, for example, the 'problem' was always with the sinister, alien force, out there in the ether, rather than inside human beings. In The West Wing, we saw an essentially positive anthropology – people are basically good. House of Cards turns that on its head – in that sense it's in the Augustinian/Calvinist tradition of declaring original sin and the "total depravity" of human beings.

Why are there so many TV shows right now which deal with sin so graphically? Maybe the 21st century is more cynical than ever. Maybe it's because the depth a TV show can reach into a character's back story and motivations is many times more than can be offered by a 90-minute film.

But maybe we're just remembering as a culture some insights of the Christian worldview which has shaped Western culture, for good and bad, for nearly 2,000 years.