I've said it before, and I'll say it again: sin is a rarely breached topic in the church, yet it is of eternal importance. A few days ago, I tried to define "good and evil," but doing so using only biblical terms. Today, I'm going to try and tackle Sin in the same regard. Sin, biblically speaking, is anything done apart from God's will. It doesn't matter WHAT it is being done, whether something WE think as "good or bad," Sin is anything apart from the will of God. Saul did what God told him to do, but on his own terms instead of exactly how God told him to do it and lost his kingdom (1 Samuel 15). King Uzziah tried to offer priestly offerings, and his forehead broke out in leprosy (2 Chronicles 26). In His sermon on the Mount, Jesus defines good deeds, prayer, and fasting as sin if done for the sake of being seen by others (they that do these things have already received their reward in full, Matthew 6). Ananias and Saphira offered a portion of the profits of their land, and were struck dead (Acts 5:1-11).
Each of these acts were considered, in worldly standards as "good acts," and even might have been profitable or charitable, yet they were all done for personal gratification, and not in obedience to or reverence of God, not on His terms. That is the nature of Sin. We can be in church our entire lives, and yet miss this key point (and thus miss out on eternity, Matthew 7:21-23). Jesus' whole point in such illustrations and sermons, and pointing people to His Father's will was this: if you TRULY know God, you'll do what He desires. If you're truly for yourself, it doesn't matter how religious you are, your church attendance, your giving, or your service, if you don't do as He says, you don't know Him, you don't love Him (John 14:15). When Jesus says "Go and Sin No More" or anything similar, when He says "follow me," He is asking for volunteers who will trust Him enough to obey Him explicitly. It's His way, or it's my way, and, sorry Mr. Sinatra, doing it my way leads to my own destruction.
So if there is any encouragement in Christ, any comfort from love, any participation in the Spirit, any affection and sympathy, complete my joy by being of the same mind, having the same love, being in full accord and of one mind. Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. Let each of you look not only to his own interests, but also to the interests of others. Have this mind among yourselves, which is yours in Christ Jesus, who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant,[c] being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.