:: Doctrine
By reading the bible the Believer has been shown that 'doctrine' is the whole counsel of God. It includes every word of the Christian Bible, which is all useful for teaching - as 2 Timothy 3:16 tells us - without exception and without alteration.
Now that the Believer understands something about 'doctrine' he/she is in a position to examine those aspects of doctrine shown to us in scripture which can, for human study purposes, be referred to as various 'teachings', i.e. the teaching on Salvation, Trinity,the teaching on Creation and so on. Each teaching is a part of the whole doctrine of God and cannot be separated or removed from it.God's word is enduring, unalterable and timeless in meaning.
I think without a true doctrine a person will end up in a cult, They will fall away from Jesus Christ and make a jesus of their own that the scripture will not justify. I feel like if someone does not teach sound biblical doctrine they are not true followers of Jesus Christ and his true gospel.
2 John 1:9 - Any one who goes ahead and does not abide in the doctrine of Christ does not have God; he who abides in the doctrine has both the Father and the Son.
2 John 1:10 - If any one comes to you and does not bring this doctrine, do not receive him into the house or give him any greeting;
Titus 2:1 - But as for you, teach what befits sound doctrine.
Romans 16:17 - I appeal to you, brethren, to take note of those who create dissensions and difficulties, in opposition to the doctrine which you have been taught; avoid them. .
Ephesians 4:14 - so that we may no longer be children, tossed to and fro and carried about with every wind of doctrine, by the cunning of men, by their craftiness in deceitful wiles.
1 Timothy 1:3 - As I urged you when I was going to Macedonia, remain at Ephesus that you may charge certain persons not to teach any different doctrine,
1 Timothy 1:10 - immoral persons, sodomites, kidnapers, liars, perjurers, and whatever else is contrary to sound doctrine,
1 Timothy 4:1 - Now the Spirit expressly says that in later times some will depart from the faith by giving heed to deceitful spirits and doctrines of demons,
1 Timothy 4:6 - If you put these instructions before the brethren, you will be a good minister of Christ Jesus, nourished on the words of the faith and of the good doctrine which you have followed.
Titus 1:9 - he must hold firm to the sure word as taught, so that he may be able to give instruction in sound doctrine and also to confute those who contradict it.
2 Peter 2:1 - But false prophets also arose among the people, just as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Master who bought them, bringing upon themselves swift destruction.
Have you ever looked at that word "secretly" ("privily" in the KJV)? The original Greek word; pareisago, means in a stealthy surreptitiously manner. Unnoticed by most Christians, these and other heresies enter continually. Their favorite excuse is to demean or accuse those who sound the alarms as "radicals" and "fundamentalists" judging others. Today, the word "fundamentalist" is a "nasty" un-PC word in most Christian circles yet, God's Word insists on any who follow Christ to be a deep "fundamentalist" locked into His Word more than we are to life and food. That in not following His "fundamental" Truth only found in His Word, we risk our life and Faith in Him by leaning upon these heresies that enter in not by the straight and narrow.
That’s why it is critical to have a solid biblical doctrine to hold on to, or else we will be lead by every wind of doctrine and at the end fall from the truth.