This is a faithful saying, and these things I will that thou affirm constantly, that they which have believed in God might be careful to maintain good works. These things are good and profitable unto men. But avoid foolish questions, and genealogies, and contentions, and strivings about the law; for they are unprofitable and vain. A man that is an heretick after the first and second admonition reject. Knowing that he that is such is subverted, and sinneth, being condemned of himself. Titus 3:8-12
Ever learning, and never able to come to the knowledge of the truth. II Tim 3:7
Heresy according to the Webster’s 1828 dictionary means “A fundamental error in religion, or an error of opinion respecting some fundamental doctrine of religion.” The best way to fight against heresy is to maintain good works, live a holy life, and be obedient to the commandments of the Lord according to Titus. If you have ever dealt with hereticks, you find out quickly why they have doctrinal problems. It is often because they get locked into an error and are ever learning but never able to figure out the truth. If you ask them, they are the expert at everything. They will gladly tell you everything they think they know. It is not that they don’t study. The typical heretics gets wrapped up in all kinds of foolish questions, strivings, and vain things as mentioned in Titus. It is just they cannot put line upon line and pull the Bible as a whole together. The reason false doctrine and heresy is so appealing is it appeals to the ego and pride of man. The Bible says knowledge puffeth up.
Hereticks lose their sense of reason at some point in life and often have trouble recovering from this snare of the devil. If you are constantly studying the Bible and not able to figure out the truth, I would say you have lost your sense of reason. That is why when dealing with hereticks common sense, logic and explanations from the Word of God will not work. Good Bible doctrine is built line upon line, precept upon precept. The Bible will interpret itself. When someone starts to use circular reasoning with two or three verses out of context to defend a key error, they are in trouble. They have lost their sense of reason. Pride will cause one not to see the truth when someone tries to tell them.
The Bible tells us our responsibility is to admonish a heretick two times. After that they are to be rejected. They are not going to change. God knows that they are subverted and living a life of sin. They are condemned not just of God for rejecting his son, but they are condemned of themselves. They took themselves out through their pride. They shot themselves in the foot by not listening to the truth of the Word of God and started making things up to feed their vain imagination. That is a bad place to be. Please make sure you never get to the point you reject the Word of God and sound doctrine.