Orthodox and Catholics apologist readily quote a few Biblical verses to support their claims to traditions.
2 Thess. 2:15
So then, brethren, stand firm and hold to the traditions which you were taught, whether by word of mouth or by letter from us.
The first issue is that granted the Orthodox or Catholics interpretations of these verses doesn’t mean that their traditions are the ones the apostle is speaking about. I find it ironic that they both have different traditions and claim that tradition is on their side. Who are you going to believe? The Eastern Orthodox? The Oriental Orthodox? The Roman Catholic? The different factions with them? The liberals? The conservatives? The Thomist? The Sedevacantist? The Franciscans? Which Eastern Orthodox church’s traditions are we to accept? The other issue is that these words are spoken to individuals with verbal access to Paul the Apostle, but last time I checked Paul died. Unless these groups think he is still around we really aren’t able to do this command and it is only for those who were verbally taught by Paul. That is a big difference because this deals with firsthand oral teachings and not second or third-hand teachings. The Papist and Orthodox drones wish for you to swallow their fideistic ideas that these traditions return to the apostles. The other issue is why suppose that they aren’t the same messages but in two different means of communication? Furthermore, the reason Paul is even saying this statement is that false ‘apostolic traditions’ have arisen( 2 Thess. 2:1-3, 3:17). So, how do we demarcate false traditions from real traditions? If the Church does, then how does the church do it? How do they determine it? Isn’t this a letter written to a Church that was instructed by Paul himself? I suppose the final thing to note with this verse is that many think that the traditions here refer to the Gospel message.
(1) kerygmatic tradition, that is, tradition concerning the central gospel message (e.g., 1 Cor. 15:1–3);(2) Church tradition, that is, tradition passed on to govern the practice of the Church (e.g., 1 Cor. 11:23–25); and (3) ethical tradition, that is, tradition dealing with proper behavior for Christians (e.g., 1 Cor. 7:10; 11:2; 1 Thes. 4:1). If, as seems likely, we are to see v. 15 in terms of the broader context of chap. 2, then we probably have a reference specifically to the kerygmatic traditions associated with the parousia of Christ. The fact that the command to keep these traditions represents an inference drawn from the discussion of salvation in vv. 13f. implies that nothing less than the salvation of the Thessalonians depended on their holding to these traditions. (In 3:7 Paul refers to a different type of tradition which he had passed on to his readers and to which he expected them to adhere, namely, a tradition regarding proper Christian conduct.)
Wanamaker, C. A. (1990). The Epistles to the Thessalonians: a commentary on the Greek text (pp. 268–269). Grand Rapids, MI: W.B. Eerdmans.
GeneMBridges – Hold Fast the Traditions
Dr. James White- Sola Scriptura in Light of 2 Thessalonians 2:15 and 2 Timothy 3:16-17
The Council 