What does Paul mean by oral and written tradition?

He is correcting alarm about the Day of the Lord, then tells the believers to hold to what Paul and his companions taught them by word or letter.

You place verse 15 in its argument: the instruction follows Paul’s correction and encouragement. Now state exactly what the verse says before drawing conclusions about later authority.

Paul is laying out a permanent church office that will preserve unwritten teachings for all future generations.

That may be part of a later theological account, but the immediate context addresses the Thessalonian believers. The verse does not describe a future office or spell out a succession process.

Yes. Paul tells these hearers to hold the apostolic instruction whether it reached them orally or in writing. The verse does not list which teachings were exclusive to either form.

That captures the clear point without claiming the verse provides an inventory. Keep the question of later preservation separate.

No. The oral teaching only counted if it was later repeated in a letter.

Paul does not add that condition in verse 15. A Protestant can argue that apostolic teaching is preserved for later Christians in Scripture, but that is an additional claim about the enduring norm.

The OPC, WELS, and Reformed writers can affirm that oral and written apostolic teaching bound the first hearers, identify its content as the gospel, and argue the apostolic writings are the enduring rule for the church.

You grant the force of the verse and describe the Protestant account as a reasoned claim about transmission and the post-apostolic period. You can now ask what supports that transition.

Protestants ignore the verse because they reject everything not written in the Bible.

That misstates their view. These sources acknowledge apostolic oral teaching and argue about how its authority reaches later Christians. Engage that argument rather than assigning a motive.

Dei Verbum says the apostles handed on the gospel orally and in writing. Scripture and Tradition form one deposit that the teaching office serves and authentically interprets.

You identify the Catholic claim about how apostolic teaching reached later Christians. The next question is what establishes the claimed authority of the teaching office.

Catholics say later church leaders can invent teachings unrelated to the apostles and put them above the Bible.

That is a polemical distortion. The council claims continuity with apostolic transmission and says the teaching office is not above the word of God.

The passage shows that oral apostolic teaching could be authoritative, but not that a modern succession exists. LDS claims of continuing revelation need their own biblical, historical, and spiritual evaluation.

You identify what the verse contributes without making it carry the whole Restoration case. Distinguish possibility from evidence that authority was restored and is exercised now.

Since the apostles taught orally, the LDS Church is proven to have the same authority today.

The first clause concerns Paul and his companions. To reach the conclusion, show who authorized the modern messengers and what evidence supports their claim.