In many places of the Holy Scripture they talk about sin. If we ask saint John the Evangelist and Holy Apostle what is sin he tells us: `the sin is the unlawfulness.` Thus the sin is the violation and depreciation of the divine law, not of the human one. The sin is a rebellion against God and an infringement of His Law.
Anything we do or say, anything we think or imagine and it is not in accordance with the law of God, is a sin. My brother, when God tells us for instance, not to lie and we lie, when He tells us not to curse and we curse, not to steal and we steal, not to do wrong and we do wrong, when He tells us not to commit adultery, not to practice debauchery and we live in debauchery and fornication, when we are reckless towards our salvation and we don`t go to the church, don`t pray, don`t repent, don`t confess, don`t commune with the Body and Blood of Christ, so when we commit so many misdeeds, don`t we sin?
Don`t we infringe the law? Don`t we resemble those people who tell God: `Go away from us. We do not want to know Your ways! Meaning: `Go away from me, God, because I don`t want to know Your ways on which you want the man to walk. `
My brother, know that every time we sin, we offend and despise God and we rebel against our Creator. That`s why we should not complain if our life is full of sorrows, trials and diseases. Saint Paul, the Apostle of God tells us:
Tribulation and anguish upon every soul of man that doeth evil 
And saint John Chrysostom tells us as well:
`The sins are the root of all evil. For sins we have sorrows, for sins we have troubles, for sins we have diseases and all irrational passions which rule us and which are hardly healed. In the same time sin causes loss. It causes sadness and all kinds of misfortunes. Yes, my brother, the sin is the drug which kills the soul
 I In. 3, 4.
 Jov. 21, 14.
 Rom. 2, 9.
Excerpt from I have sinned, my God, please receive me who repent– Hieromonk Kosmas, Evanghelismos Publishing.