Welpt.... I would think you would start with the doctrine of sola scripture itself.... where's that at? when has that even been proven to be true using scripture alone?...
2 Timothy 3:16-17
[
16]
All scripture is inspired by God and profitable for teaching, for reproof, for correction, and for training in righteousness,
[
17]
that the man of God may be complete, equipped for every good work.
Notice it says that the man of God may be complete. The man of God is a regenerate man who has been reborn. Also to be complete means you don't need to add anything to it.
John 10:27
[
27] Mysheep hear my voice, and I know them, and they follow me;
Christ says scripture cannot be broken.
John 10:35
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35] If he called them gods to whom the word of God came (and
scripture cannot be broken),
Peter clearly says scripture will be left so that the apostolic teachings can be remembered.
2 Peter 1:10-21
[
10] Therefore, brethren, be the more zealous to confirm your call and election, for if you do this you will never fall;
[
11] so there will be richly provided for you an entrance into the eternal kingdom of our Lord and Savior Jesus Christ.
Above Peter reminds the elect to be more zealous to confirm their election which meant to live for Christ. Only the elect really want to do that.
[
12] Therefore I intend always to remind you of these things, though you know them and are established in the truth that you have.
[
13] I think it right, as long as I am in this body, to arouse you by way of reminder,
[
14] since I know that the putting off of my body will be soon, as our Lord Jesus Christ showed me.
[
15] And I will see to it that after my departure you may be able at any time to recall these things.
Above Peter says that he will make sure we will be able to recall apostolic teachings after the death of him and the apostles.
[
16] For we did not follow cleverly devised myths when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty.
[
17] For when he received honor and glory from God the Father and the voice was borne to him by the Majestic Glory, "This is my beloved Son, with whom I am well pleased,"
[
18] we heard this voice borne from heaven, for we were with him on the holy mountain.
Above he established authority in the fact that he and the apostles were eyewitnesses of Christ.
[
19] And we have the prophetic word made more sure. You will do well to pay attention to this as to a lamp shining in a dark place, until the day dawns and the morning star rises in your hearts.
Above Peter claims that the apostles have the prophetic word which means they are like those prophets of old who wrote scripture inspired by God.
[
20] First of all you must understand this, that no prophecy of scripture is a matter of one's own interpretation,
[
21] because no prophecy ever came by the impulse of man, but men moved by the Holy Spirit spoke from God.
After establishing his authority firmly Peter reveals the plan. He and the apostles are writing and are going to write scripture to be followed.
He assures the reader that the writer of scripture didn't write his own interpretation of the inspiration of the Spirit. He says that men who write scripture are moved by the Holy Spirit to speak from God. Roman Catholic apologists love to twist this in an attemot to make the listener believe that this means that scripture cannot be interpreted by one. It means that the WRITER did not follow his own interpretations instead he followed the inspiration of the Spirit.
Now many Catholics would object that the bible says this:
2 Thessalonians 2:15
[
15] So then, brethren, stand firm and hold to the traditions which you were taught by us, either byword of mouth or by letter.
Well, if one was lucky enough to stand in the presence of the Apostles of Christ and listen to a Holy Spirit inspired sermon by one of the eyewitnesses that person could indeed hold fast to that authoritative word that they heard from the lips of the apostles.
What happens when all the apostles are dead?
All you have left now is the Authoritative apostlolic traditions and teachings that are in the written letter! Since the mouth is in the grave awaiting the resurrection we are left only with the letter if we want to hear apostolic teachings at all.
Sola Scriptura is the only (sola) way to get authentic apostolic teachings and the only way available to the honest christian to hold fast to the authentic traditions taught by the apostles. God inspired them to write infallible scripture accounts of the things they witnessed with their own eyes.
No teacher today has that authority or that unique blessing from God.
The Sola Scriptura doctrine is biblical and obvious.