For simplicity, I'll define a sin as an offence against the self.
What better place to start than lust? A lovely thing, in my opinion, if occasionally uncomfortable. Although I admit it can lead us into strife, I think the Christian moralists protested too much, especially since most of them saw lust as the worst of the seven. It seems to me that the Christian injunction against lust is based on the anti-life attitudes that became entrenched in religious thinking. Putting it a little simplistically, much of Christian teaching can be reduced to, "Do not desire things in this unimportant earthly existence, your rewards for self-denial will come in the ever-lasting."
Please note that my comments about Christianity refer to the old-fashioned variety, the one that gave us the crusades, the immaculate conception and Guilt with a capital 'g'. In my opinion, such a form of Christianity has little to do with the teachings of Christ, who said: "Pass no more judgements upon other people so that you may not have judgement passed upon you." It is well to remember that it was St Paul, not Christ, who established the religion called Christianity. Christ died a Jew.
Anger is another basic human feeling disapproved of by Christian doctrine. If we are here only to obey the word of God then what right have we to get angry? Yet anger can be a highly appropriate and healthy reaction. Modern psychology holds that suppression of anger is unhealthy and destructive to the individual concerned. Anger can help heal an emotional injury by empowering us to stand up for ourselves and stop putting up with the pain we are experiencing. It can break through a fixed pattern in a relationship by ensuring that our feelings are given more weight.
Sloth is hardly something to brag about. However, I think that sloth or laziness is better understood as a lack of motivation, than as a sin in its own right. This runs counter to the Christian view - that what a person is supposed to do is laid down by God and they simply must do it. Motivation is not in the picture.
Pride is not to be confused with self-respect and self-esteem. We commit the sin of pride when we lose our humility. Pride is holding oneself and one's achievements above other people. As such, it acts as a barrier and tends to make us smug, superior and rigid. It is indeed the cause of much misery and destructiveness. Salman Rushdie wrote, "Men will sacrifice their deepest love on the implacable altar of their pride." However, I think the sin of pride is better understood in terms of ego, described below.
Envy undoubtedly eats us up from inside and makes us unhappy. It also gives rise to the pernicious feeling that "this is not it". Someone else has "it", but we do not. Again, however, envy is part of a more general sin, the sin of not living in the present. For whenever we experience envy, we turn away from the present by comparing it with something we would rather have.
Covetousness I divide into avarice and desire. So long as we remain humans, not saints (or buddhas), we will have wants or desires. Guatama the Buddha argued that desire is the ultimate cause of all suffering, and who am I to disagree? Be that as it may, I prefer the more moderate course of castigating avarice. Like envy, avarice makes us unhappy by giving us yearnings that can never be satisfied, called deficit needs. Someone pointed out that you can never get enough of what you don't really need. I include avarice within a broader sin, defined by Fromm as the Having Mode.
Gluttony is grossly uninteresting and merely a special case of avarice.
So much for the traditional Deadly Sins. Here is my own list: ego, guilt, self-pity, blame, negativity, Having Mode and not living in the present. Obviously, this list could be made much longer, e.g. suicide is the result of an extremely self-destructive feeling. However, seven is the traditional number and I think it's best not to adjust it for inflation. I dub the above the Seven Modern Sins.
I use the word ego in its colloquial sense, as in, "He boasts because he has ego problems." The ego is a false sense of identity, a pretence we try hard to maintain. It is ego that stops us from admitting it when we are wrong. Thus we might prefer to lose a friend than an argument. Perhaps the clearest example of ego at work is when we try to save face. Ego is a sense of false pride that masks a deeper insecurity. Whenever we are defensive we are acting from the ego. For the ego is like an inflated balloon we constantly guard against being pricked. Ego is a fragile narcissism that can cost us dearly. Especially if it causes us to lust for power. Ego is best summed up as the attitude of preferring to be right than to be happy. Freedom means giving up our ego.
Guilt is a form of self-punishment. It is highly destructive because it makes us feel unworthy. Although guilt can cause us to do good, such as making reparations, it is psychologically destructive. It traps us in a web of 'should's and 'must's. Guilt is also an unnecessary emotion. Apparently it is not a 'primary' emotion like anger or sadness, but an emotion we learn to experience. It is also an emotion that is easily manipulated. Guilt fixates us on the past, which is unchangeable, and disempowers us so that we do not act in the present, where change is possible. Guilt is self-condemnation, and as such it has the opposite effect to understanding. Instead of helping us grow, guilt causes us to contract.
Old-fashioned Christianity made a virtue of guilt because it saw human nature as essentially flawed. Guilt was needed to ensure people did the right thing. Nowadays, quite a different paradigm of human nature is emerging, one that renders guilt unnecessary.
Self-pity is a purely destructive feeling, very similar to guilt. It makes one feel a powerless victim, unable to make any effort to help oneself. Both guilt and self-pity are forms of regret, which is always locked into the past. Hence they make it more difficult to solve problems in the present.
Blame is like guilt, except that it is directed against others. By antagonising other people it effectively shifts the focus from solving problems to creating them. Simply put, it adds insult to injury. Also, by focusing on others we avoid taking responsibility for our own role. Note that cynicism and sarcasm are expressions of blame. In fact, sarcasm has been characterized as "barely concealed hostility".
Negativity characterises some people's orientation to life. We can see a glass as half empty or half full. Some of us live a life of half empty glasses. This often shows in self-putdowns like, "I'm no good with my hands". Negativity is closely linked with pessimism. Yet its opposite, positivity is quite different from optimism. Optimism is an unrealistic attitude of expecting something better than what we can reasonably expect. Positivity is not an expectation but an attitude to what actually does happen, whether this is to our liking or not. Thus you can be positive about breaking your leg, eg it gives you time to reflect, your friends see you, it takes away certain responsibilities. Positivity is incredibly important because if you can more or less gladly accept all that happens to you, how will you ever manage to be miserable? Or to put it in another way, if you trust that life always brings you what you need (not to be confused with what you want), then you are most likely a happy person.
Negativity often manifests as insecurity, a kind of inappropriate fear that most of us seem to suffer from in various forms. Like most of the other Modern Sins, it causes us to contract and withdraw into ourselves. The opposite of insecurity is confidence, the feeling we can do things effectively. Confidence tends to act as a self-fulfilling prophecy. Insecurity also works this way, but in the opposite direction. An insecure person tends to find that their fears are often confirmed. Yet it is not the external world that is to blame, but the attitudes the person carries within them.
The Having Mode is a fundamental orientation to life where not only material objects, but also knowledge, opinions, relationships, memories, habits and even feelings are treated as possessions, whose loss we fear. A tourist is in the Having Mode if they are more intent on photographing what they see than on actually experiencing it. A similar example is taking notes at the expense of absorbing a lecture. Marriages often founder because the couple take each other for granted, as if they each "had" the other. Doctors are notorious for the jealous way they guard their knowledge, keeping their patients in ignorance. When two people are arguing in the Having Mode, each is intent on assailing the other's opinion but has not the faintest intention of changing their own.
Of course, the most obvious and pervasive form of the Having Mode is the way that people chase after material wealth, as if it were an end, rather than a means. This ultimately leads to people being owned by their possessions. A person caught up in the Having Mode impoverishes their experience by relating to everything in their life as to lifeless objects. For only objects can be owned. A beautiful Indian proverb embodies the negation of possessiveness: "All that is not given is lost."
Perhaps the most endemic sin of all is not living in the present. I'll call this Absence, for want of a better word. Most of us spend a lot of time living in the past, replaying, regretting or savouring it. Of course it isn't possible to live in the past - what we do is to ignore the present, which is actually all around us, in order to focus on the past, which has no existence except in our memories or other records. The result is that we do not function effectively in the present, the only place where it is possible to do anything. The past is safer and easier to deal with because it is fixed and known, whereas the present is ever fluid and only discovered as we live it, never ahead of time.
The other form of Absence is living in the future. This is equally futile since the future too has no existence except in our minds. All forms of fear are actually experiences of living in the future. It is not possible to fear anything in the present because the present already is, and therefore nothing worse can happen in it. A present situation might cause us anguish or pain, but not fear.
Apart from this, feeling a fear is usually a far more unpleasant experience than what actually happens, even if exactly what we feared comes to pass. In my own experience, it has hardly ever happened that an event I feared turned out to be worse than my experience of fearing it beforehand. While we are nearly always able to cope with the present, fear - our negative expectations about the future - can be far more traumatic.
I am not saying that learning from the past or planning for the future are to be avoided. Living in the past or the future means neglecting the present by focusing instead on what was or what we expect might be. Not living in the present means a life of waiting. As Russell Hoban observed, "There is no such thing as an in-between time."
The Seven Deadly Sins were held to be deadly because if we died with them unconfessed, they would consign us to Hell. Perhaps the Seven Modern Sins do not threaten our fortunes after the change called death, but they have a hell of a lot to do with causing our misery while we are still here on the planet.