I don't usually sin, but when I do, it's because I'm human. Actually, I sin a lot. In fact, I'm prolly sinning right now. What, you may wonder, am I doing right now that qualifies as sinning? Well, the way I see it, everyone has a relationship with sin in some manner that varies in its visibility to the individual.
Sin is, in short, missing the mark. It is imperfection. If you're not comfortable with the word sin, then maybe let's just go with "nobody's perfect" and leave it there. So, when I use the word sin, just think about "nobody's perfect."
My relationship with sin varies in awareness and likeliness to engage in it. Here are a few ways I think about sin.
Obvious Sin; No Temptation: There are some sins that are so obviously sin, murder for example, that almost everyone would agree that they are indeed sin. Furthermore, I have never been drawn to murder. It has not been a temptation for me. I hope it never is. The odds of my murdering are low, but of course still possible.
Obvious Sin; Temptation: There are some sins that are obviously sin, selfishness for example, that almost everyone would agree that they are indeed sin. For me, it is so very easy to miss the mark on this one. I am selfish. I know that act on self-interest. I take too much and give too little. It is a real problem. I know it is a problem. I do it anyway.
Obscured Sin; Oblivious: Here is a tricky one. This is the one when I am sinning and I don't even know it. It is either due to a lack of awareness that whatever it is I am doing is sin or that I am sinning and do not realize what I am doing. I am either unaware of sin or unaware of myself.
Obscured Sin; Promoted as Though a Virtue: This one is even more tricky. Greed, for example, unless you're Gordon Gekko, we can all agree greed is bad. What we cannot easily agree on is the definition of greed. What we cannot easily see, especially Americans who live in capitalism like a fish lives in water, is how greed operates, how systems of greed make sin so normal it is espoused and defended (sometimes in the name of God) as virtue. I am a participant in this sin, promoter of this sin, and in the rare moments when I find some vague awareness of this sin, I find it next to impossible to get out of it. But most of the time I am not even aware of it.
This last sin is more abstract than what are more often understood as behavioral sins. It is a system or process of sin. It is a condition of culture on some level that situates people into missing the mark, but in a way so nuanced and subtle that it may be experienced as normal or even virtuous.
So, yep, I'm prolly sinning right now.
Now, here is the kicker. What is obviously sin to me might be in some other category for another person. I might know X to be sin when another person might see the sin X as a virtue - and vice versa.