Nor does it say anywhere that oral teachings are encapsulated completely within the Scriptures. This is a Protestant assumption that is proven incorrect based on the writings of the first Christians.
So what are the Oral traditions that were not written down?
“”So what are the Oral traditions that were not written down?””
Everything was an oral tradition before any Scripture was ever written .Some things are clear in Scripture and some things are not.It is the Church that DEFINES with clarity
The Trinity is an example
The Trinity is not clearly defined in Scripture,thus you have had Arians and modern day Trinity deniers to this day denying this.
If you look to the Church Tradition the Trinity is clear because the Church ALWAYS knew it by Tradition
When did the Church declare that Jesus was God as dogma? At the council of Nicea in 325 AD. Nearly 300 years after Christ’s death, correct? Does that mean that the Church DID NOT already believe this? Of course it did! Jesus was worshiped during the liturgy. People prayed to Him during their daily prayers and through their actions. The Church already KNEW that Jesus was God - the Church DEFINES that He was God infallibly based on the guidance of the Spirit ALREADY AT WORK in the Church. The Church defines dogma to authoritative say what we believe, just like it did with the contents of Scripture. The Church already had a good idea of what it was, but now, they had an authoritative decision.
Here is a few writings from Church Fathers defending traditions...
ST. IRENAEUS OF LYONS (c. 180 AD):
“So forceful are these arguments that no one should henceforth seek the truth from ANY OTHER SOURCE since it would be simple to get it from THE CHURCH ....On this account are we bound to avoid them, but to make choice of the things pertaining to the Church with utmost diligence, and to lay hold of the TRADITION OF TRUTH ..For how should it be if the Apostles themselves had not left us writing? Would it be necessary [in that case] to follow the course of Tradition which they handed down to those whom they committed the Churches?” (Against the Heresies 3:4:1)
“Though none others know we the disposition of our salvation, than those through whom the Gospel came to us, first heralding it, then by the will of God delivering us the Scriptures, which were to be the foundation and pillar of our faith. ...But when the heretics use Scriptures, as if they were wrong and unauthoritative, and we variable, and the truth could not be extracted from them by those who were IGNORANT OF TRADITION. And when we challenge them in turn with that TRADITION, which is FROM THE APOSTLES, which is guarded by the succession of presbyters in the churches, they oppose themselves to TRADITION, saying they are wiser, not only than those presbyters but even than the Apostles! The TRADITION OF THE APOSTLES manifested, on the contrary, in the whole world, is open in every church to all who seeks the truth ...And since it is a long matter in a work like this to enumerate these successions, we will confute them by pointing to the TRADITION of the greatest and most ancient and universally-known Church founded and constituted at Rome by the two most glorious Apostles, Peter and Paul, a TRADITION which she has had and a faith which she proclaims to all men FROM THOSE APOSTLES.” (Against the Heresies 3:1-3)
“It comes to this, therefore, these men do not consent to either Scripture nor TRADITION.” (Against the Heresies 3:2:2).
ST. BASIL THE GREAT (c. 370)
“Of the dogmas and messages preserved in the Church, some we possess from written teaching and others we receive from the Tradition of the Apostles, handed on to us in mystery (i.e., Sacrament; the Liturgy of the Mass). . In respect to piety both are of the same force. No one will contradict any of these, no one, at any rate, who is even moderately versed in matters ecclesiastical. Indeed, were we to try to reject unwritten customs as having no great authority, we would unwittingly injure the Gospel in its vitals; or rather, we would reduce [Christian] message to a mere term.” (The Holy Spirit 27:66 [A.D. 375]).
ST. JOHN CHRYSOSTOM (c. 390)
” ‘Stand firm and hold fast to the Traditions you were taught, whether by an oral statement or by a letter’ (2 Thess 2:15). Hence it is manifest that they did not deliver all things by Epistle, but many things UNWRITTEN, and in like manner both the one and the other are worthy of credit. Therefore, let us think the TRADITION of the Church also worthy of credit. It is a Tradition, seek no farther.” (Commentary on 2nd Thessalonians NPNF 13:390).
ST. AUGUSTINE OF HIPPO (c. 400)
“Those which we keep, not as being written, but as from TRADITION, if observed by the whole of Christendom, are thereby understood to be committed to us BY THE APOSTLES themselves or plenary Councils, and to be retained as instituted.” (Ep 118).
“But in regard to those observances which we carefully attend and which the whole world keeps, and which derive not from Scripture but from Tradition, we are given to understand that they are recommended and ordained to be kept, either by the Apostles themselves or by plenary [ecumenical] councils, the authority of which is quite vital in the Church” (Letter to Januarius [A.D. 400]).
I am going to busy and traveling over the next few days,dear friend,so I might not be able to respond for awhile
I wish you a Blessed Evening!
If Catholicism's approach to date is any guide, they're anything you need them to be....