2 Thessalonians is about the truth being proclaimed by tradition, which is both by word of mouth and by the scripture. In other words, Truth -> Scripture. The relationship between Chruch and Truth is in 1 Timothy 3:15, as well as in several chapters from John.
This is 2 Thess. 2:14...
""Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ."
Nowhere in that verse is any mention made of tradition; only Scripture, only the word of God.
Perhaps you see things that aren't there.