Sound words and sound doctrine

1 Timothy 1:3 (KJV) As I besought thee to abide still at Ephesus, when I went into Macedonia, that thou mightest charge some that they teach no other doctrine,

This is the standard for teachers of God's word - not simply that they teach the doctrine to which Paul refers, but that they teach no doctrine other than this. 

And what is the doctrine that should alone be taught? The doctrine in question is that taught by Paul:

2 Timothy 1:13 (KJV) Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus.

This doctrine is found in scripture in the books from Romans to Philemon. 

Speaking "sound words" dispenses "sound doctrine":

Titus 2:1 (KJV) But speak thou the things which become sound doctrine:

It is only sound doctrine which is profitable for those who oppose (the gainsayer):

Titus 1:9 (KJV) Holding fast the faithful word as he hath been taught, that he may be able by sound doctrine both to exhort and to convince the gainsayers.

It is this sound speech and doctrine, and this alone, which is approved of by God:

Titus 2:8a (KJV) Sound speech, that cannot be condemned;