John 7:16-17 Jesus answered them and said, "My doctrine is not Mine, but His who sent Me. If anyone wills to do His will, he shall know concerning the doctrine, whether it is from God or whether I speak on My own authority."
Sound doctrines are doctrines of God, and only those who are prepared to obey Him and do His will and commands will be able to understand His doctrines. Our Lord taught sound doctrines to His disciples.
Note - All sound doctrines must conform to the whole counsel of God or truth in the word of God.
Eph 2:20 having been built on the foundation of the apostles and prophets, Jesus Christ Himself being the chief cornerstone,
Sound doctrines are the very foundation of the Apostles, which is Christ centered. Only those who teaches and practices sound doctrines can enter the new Jerusalem or the Kingdom of heaven.
Rev 21:14 Now the wall of the city (new Jerusalem) had twelve foundations, and on them were the names of the twelve apostles of the Lamb.
Lead to Godliness
1Tim 6:3-6 If anyone teaches otherwise and does not consent to wholesome words, even the words of our Lord Jesus Christ, and to the doctrine which accords with godliness, he is proud, knowing nothing, but is obsessed with disputes and arguments over words, from which come envy, strife, reviling, evil suspicions, useless wranglings of men of corrupt minds and destitute of the truth, who suppose that godliness is a means of gain. From such withdraw yourself.
Sound doctrines lead to godliness but doctrines of men and heresies are the results of disputes and arguments over words (esp. those using Hebrew and Greek to justify their own ideas). These heresies and worldly wisdom give no consideration to God's attributes, will, sayings, teachings, promises, covenants, words, and the epistles of the Apostles.
Edifies our Faith
1Tim 1:3-4 As I urged you when I went into Macedonia -- remain in Ephesus that you may charge some that they teach no other doctrine, nor give heed to fables and endless genealogies, which cause disputes rather than godly edification which is in faith.
Sound doctrines edifies our faith, but wrong doctrines, fables, etc. destroy our faith in Him and His word.
Exhort and Convict
Tit 1:9-11 holding fast the faithful word as he has been taught, that he may be able, by sound doctrine, both to exhort and convict those who contradict. For there are many insubordinate, both idle talkers and deceivers, especially those of the circumcision, whose mouths must be stopped, who subvert whole households, teaching things which they ought not, for the sake of dishonest gain.
Sound doctrines exhort us and also convict us of our ignorance in believing heresies.
Heresies - Worship in Vain
Mat 15:8-9 "'These people draw near to Me with their mouth, and honor Me with their lips, but their heart is far from Me. And in vain they worship Me, teaching as doctrines the commandments of men.'"
Brethren when we are not teaching sound doctrines, God will not accept our worship (including thanksgivings, praises, offerings, prayers, requests, intercessions, etc.), so please forget and destroy all teachings, commandments or doctrines of men taken from books, writings, videos, etc. Let's try to find the sound doctrine of each topic together by studying only the scriptures in the bible. With our submission to the Spirit of truth, we believe that He will guide us into all truth so that we will be able to expose distorted truth, wrong doctrines and heresies.