The claim is often made in popular literature that Jesus and the New Testament in general and St. Paul in particular, are hostile to tradition and the inference is then made - that they believed in a sole source of faith and morals, namely Scripture alone.
In this post we will stick to Scripture references since it is needless to marshal the Catholic Patristic Fathers who manifestly teach and defend a unified source of faith and morals, namely Sacred Tradition (oral kerygma) and Sacred Scripture (the oral teaching encapsulated in written form)1.
We read in Holy Sacred Scripture from St. Paul to the Thessalonians,
"So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter." (2 Thess 2:15, RSVCE)2.
As the context makes clear (starting from verse 1) contra those who wished to lead the Thessalonian saints into eschatological heresy3 St. Paul exhorts them to stand firm, something which they were already being known for (1:3). It is on account of those blessed gifts from God (2:13-14) that the Thessalonians can even begin to stand firm4.
"καὶ" here is surely explicative, the way to stand firm is to hold to the traditions. The Thessalonians are to hold fast to both the oral tradition (λόγου) and to the "written letter" (ἐπιστολῆς). St. Paul would never say, "by us, the letter," as if the early Christians should only live and practice the Written Scriptures5. But rather, oral tradition is the foundation for the later encapsulation of it in written form as St. Irenaeus so eloquently stated. This is because the two "sources" are simply two voices of the same teachings of Jesus Christ. A distinction between the two is purely modern and a false dichotomy.
In another place this is made again clear by the same author, he writes,
"Now I would remind you, brethren, in what terms I preached to you the gospel, which you received, in which you stand, by which you are saved, if you hold it fast - unless you believed in vain." (1 Cor 15:1-2, RSVCE).
A pericope that rings familiar to our reading in 2 Thessalonians. It is the oral proclamation which the Corinthians are to hold fast to. This point becomes even sharper if we are to believe the strong scholarly consensus that there was an earlier "lost" Corinthian letter that was written to them. Either way, St. Paul does not lift up the Scriptures nor his earlier letter but instead points to his living voice which is still ringing in their ears, the oral tradition as the measuring rod of salvation. St. Paul is not inventing a new trick but following the established apostolic norm, he continues on,
"For I delivered to you as of first importance what I also received..." (1 Cor 15:3, RSVCE).
This was a common tact of Paul, to pass along doctrine via word of mouth (1 Cor 4:17). And to uphold Christian tradition is supremely commendable,
"I commend you because you remember me in everything and maintain the traditions even as I have delivered them to you." (1 Cor 11:2, RSVCE).
In these and many other texts it is the παραδόσεις which is highlighted. It is this oral tradition which is the gauge with which the earliest Christians were to compare all doctrinal claims6.
1. A small selection of the earliest Fathers; St. Papias (Hist. Eccl. 3, 39, 3-4), St. Irenaeus (Adversus haereses. 3, 1, 1), St. Clement of Alexandria (Misc. 1, 1 ), Origen (Fund. Doct. 1, 2), Tertullian (De praescriptione haereticorum. 21, 3-7), St. Athanasius (Serapion. 1. 28).
2. The Greek reads, "ἄρα οὖν, ἀδελφοί, στήκετε, καὶ κρατεῖτε τὰς παραδόσεις ἃς ἐδιδάχθητε εἴτε διὰ λόγου εἴτε δι’ ἐπιστολῆς ἡμῶν." Most Protestant translations (literal) read similar to the RSVCE cited above.
3. And we could say Paul's entire argument in 2 Thessalonians could be used against any heresy that threatens the Church. Moreover, notice the close relation of the wording of V.2, "λόγου μήτε δι’ ἐπιστολῆς ὡς δι’ ἡμῶν" to our text in question, "λόγου εἴτε δι’ ἐπιστολῆς ἡμῶν." Already at the start of chapter 2 St. Paul has given us the argumentation of v.15 in fuller detail.
4. Hence, the "ἄρα οὖν."
5. Not to mention that at this time in Christian history the New Testament as we know it today was hardly known by all the early Churches. The majority of the citations in the earliest fathers and in the New Testament to the Scriptures refers to the Old Testament. The descriptions for the New Testament writings are usually made clear, such as Justin calling them "the memoirs of the Apostles." Here in our target text in Paul he is likely referring to 1 Thessalonians.
6. Wolfgang Trilling (Der zweite Brief and die Thessalonicher: EKKNT. 128-29) followed by much of the higher critical school that sees 2 Thessalonians as non-Pauline finds this idea of παραδόσεις so forceful and developed here that he holds that it was "clearly" written by a later redactor that tried to fit in later Catholic ecclesiology, vis a vis, the importance of oral tradition.