What is SIN?

Sin is failing to do God's will, is disobedience towards God, is missing the mark which is holiness, is to break God's laws. 1 John 3:4. In the Bible we can find different kinds of sins, like the ones mentioned in Exodus 20, called the Ten Commandments: You shall not murder; you shall not commit adultery; you shall not steal, etc. There are others mentioned in the New Testament, what the Apostle Paul called "works of the flesh": Fornication, hatred, envy, jealousies, etc. Unfortunately, the culture inside the Christian church tends to classify sin, so it's bad "to kill" but it's not too bad "to lie", it's bad "to idolize" but it's not too bad "to envy", etc. There's this concept of "white lie" that has permeated Christianity and brought with it other "acceptable" sins, making the very "purpose" or "target" called holiness to be almost "extinct" in our modern Christianity, in other words, we lack the power and glory of God in our lives and our churches because we failed to be holy: Leviticus 19:2; 1 Peter 1:15-16. As you can see, the God in the Old Testament is the same God in the New Testament, He does not change: Malachi 3:6. There's no "acceptable" sin, every sin is detestable and hateful before the Lord. We must learn to hate sin and to love holiness. If we say we love the Lord and don't love holiness we are deceiving ourselves. How can we love the Holy One (the Lord God) and don't love holiness? Isaiah 59:2. Unfortunately, along the years many false doctrines appeared in the church and harmed many people, like this one: "A Christian person does not sin". I heard this teaching over 20 years ago and i refuted such heresy when the pastor spoke it, but what broke my heart was not seeing any of the leaders (3 different churches in a youth retreat) standing against it. They did it later, but the damage was already done. We must hate sin, but at the same time acknowledge that we are sinners and sooner or latter we will sin, and when (not if) we sin we must repent and confess our sins to be forgiven. 1 John 1:8-10.