What does “doubtful disputations” mean anyway? Well... it basically means to argue over controversial subjects. The two types of people mentioned in this chapter are prone to religious arguments.
One group carries a list of sins which are exceptionally grievous to them. They will have a general list which includes sins that are held in disesteem by most people, such as adultery and murder, but they will also carry this other list. This list is more refined and detailed, and a bit harder to defend. The items on this list are generally controversial, so this list will receive much more playtime when it comes to disagreements.
An item on this list mentioned vaguely in the Bible can become the cornerstone of a church or religious movement simply because it genders controversy. The controversy drives like-minded people together, and separates them from everyone else. Some religious leaders have been known to use such controversy to keep their followers behind them. I heard one of these leaders say, “If you want people to rally around you start a fight they can believe in, and they’ll follow you to the end of the earth!”
There are a few root problems here. One is a misunderstanding of the law of God. Basically any list will be way too short, and is fundamentally flawed because it cannot contain the fullness and essential essence of God's law. Our Creator is the source of all law. Law in its fullness is the expression of His being or personality. As living, intelligent beings the standard of perfection for us cannot be fully expressed by a list. The standard is a person.
Jesus put it this way: “Be ye therefore perfect, even as your Father which is in heaven is perfect.” Matthew 5:48 The standard we must meet is the full moral perfection of God. That perfection cannot be fully boiled down to a list of behaviors, because it involves more than behavior. Moral perfection comprehends motives, balance, appetites, responses, absolute control of our physical being, and a thousand other realities of what it means to be an intelligent, moral creature.
The remedy for those who wish to argue over their list is to be given more law than they can walk out the door with. Defending an obey-able list of behaviors makes a person feel strong, secure, and... well... self-righteous. But when the living standard of the law is discussed we immediately become aware of our deep imperfections, and our inability to ever meet the moral perfection required by God. A basic understanding of the law robs us of any self-righteousness.
Then we must find righteousness from some other source than self in order to be reconciled with God. This is where Jesus and His gospel come into play. He died to permanently remove our guilt, and to replace our moral imperfection, in the sight of God, with full, absolute perfection which comes by faith not behavior. Gospel means “good news,” and it is truly good news to anyone who has faced the living law of God. Look at these verses:
Romans 3:19 Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God. 20 Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin. 21 ¶ But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets; 22 Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference: 23 For all have sinned, and come short of the glory of God;
2 Corinthians 5:21 For he (God The Father) hath made him (Jesus Christ) to be sin for us, who knew no sin; that we might be made the righteousness of God in him. (Parenthesis mine for contextual information)