Finding what is sin and what is not sin in the bible:
Regarding "direct sin". In the Old Testament, it mentioned what foods we can and cannot eat and how those foods must be prepared and eaten. In the New Testament, "What God has cleansed, no longer consider unholy." This mean that the meats formerly considered unclean were now cleansed. (Read Acts, Chapter 10). Under the old testament LAW cannot eat certain food (example: pork) however under the new testament GRACE, we can eat pork.
The New Testament (Reference: Book of Galatians, Chapter 5) speaks about the believer's freedom or liberty in Christ, but what exactly does this mean biblically speaking for the Christian? Christian liberty means the power to do as we ought by God's enablement in accordance with the way Christians have been recreated in Christ. True liberty means the freedom to be all that we were designed to be, but this is not a freedom that is without restrictions or responsibilities. Plainly speaking, without law, there could be no freedom.
"One of the marks of maturity is the ability to disagree without becoming disagreeable. It takes grace. In fact, handling disagreements with tact is one of the crowning achievements of grace." Chuck Swindoll
Charles Swindoll paraphrases the main points of Romans 14 in his book "The Grace Awakening:"
"Nothing that is not specifically designated as evil in Scripture is evil but rather a matter of one's personal preference or taste. So let it be. Even if you personally would not do what another is doing, let it be. And you who feel the freedom to do so, don't flaunt it or mock those who disagree. We are in the construction business, not destruction. And let's all remember that God's big-picture kingdom plan is not being shaped by small things like what one person prefers over another, but by large things, like righteousness and peace and joy."
We don't want to be a legalistic about our Christian daily life at the same time we don't want to abuse our Christian liberty. Christian Legalists cannot change a heart, it tries to control people with laws and expectations that are not even kept by the religionists who interpret and apply the rules. With this "burden factor" in mind, Jesus said, "Woe to you also, lawyers [experts in religious law]! For you load men with burdens hard to bear, and you yourselves do not touch the burdens with one of your fingers" (Luke 11:46). Religion is good at describing high standards of right behavior and relationships, but poor at giving real and merciful help to those who realize they have not lived up to those expectations.
We have to understand that God saves people even though they are yet sinners (Rom.5:1-11). However, He does not simply leave them in their sins, but rather, forgives their sins and imputes to them the righteousness of Christ (Rom. 4). God wants us to declare ourselves alive in the Spirit, confession that there is a new life within us. "If we live in the Spirit, let us also walk in the Spirit." Galatians 5:25. We are not only to live the deadness of our old life, we are also to recognize the new person who lives within us. The Holy Spirit dwells in us with all the power and gifts of God, necessary to enable us to walk the noble, spiritual, Son-like life with God.
By grace He brings them into the family of God and starts the process of transforming them into the image of Jesus Christ (Rom. 8:28,29). The Biblical process of solving personality and behavioral problems begins with God's Word revealing our hearts (James 1:21-25, Heb. 4:12). At that point we can then go to the real Christ for grace, mercy and help (Heb. 4:13-16). Then as the real Holy Spirit ministers in our lives through the Word of God, we will grow in abundant life and godliness (II Pet. 1:3) and become adequate for every good work (II Tim. 3:16,17). Read Romans Chapters 12, 13, 14 and 15 and Book of Galatians because they teach believers to have a real relationship with God. You can enjoy living a Christian life without being a legalist. Have a relationship with Jesus Christ, your Lord and Savior.