"Sin" is a spiritual disease. It is a twisted, bent, broken aspect of our being, deep in our soul.
"Sin" can have symptoms (often called "sinS"). Thoughts, words and deeds. Attitudes, passions. Stuff done/thought/felt/said that should not be so.... stuff not done/felt/thought/said that should have been so. Let's say I have a cold (I don't; I almost never do - but run with me here)..... It's a disease (for which there is no cure). Now, I MAY be coughing, sneezing... I may have a runny nose and a sore throat. I may not. But with or without noticeable symptoms, I have a cold.... a disease.... something is WRONG with ME. In the same way, ALL of us have a disease: sin. Most of us have quite profound symptoms.
"Sin" is much, much more than just some outward, technical, observable violation of the Ten Big Ones... If I shoot my neighbor (and the thought has crossed my mind) the "sin" is not that a finger that just so happens is attached to a body part technically belonging to me caused a gun to fire - and now my neighbor is dead. Nope. The sin happened LONG, LONG before that.... in my heart, my soul, my being.... that meant I do not LOVE my neighbor as myself.... I do NOT do all to help and defend and promote and aid my neighbor.... I do NOT honor life preciously.... I HATE this dude, I want him DEAD. So I thought up my plan.... I got my gun... I waited my opportunity..... Ah..... The Pharisees considered sin just an outward TECHNICALITY and considered themselves quite goody-goody (and thus in no need of God or grace or mercy or forgiveness or the Savior). Jesus reminded them: sin comes from the INSIDE, it's INSIDE of us.... some bent, twisted, broken sickness.
Lord, have mercy.
Christ, have mercy.
Lord, have mercy.
"I am the CHIEF of sinners" - St. Paul
- Josiah