Read to all. 1st Thessalonians 5:27 When strong language is used, such as a “charge,” the matter being addressed must be regarded as very important. Every believer in the Thessalonica assembly needed to hear the words of this letter. It was probably read aloud during a public meeting, so everyone heard the messages and the responses to their concerns. Paul wanted all of them to hear his advice, his concern, and his encouragement.
The truth shared in this epistle is also for us—to learn and be warned. Biblically, there are no secrets in Christianity. Sadly, some so-called Christian groups have secret codes, handshakes, and signals to hide their beliefs, practices, and instructions from outsiders. This is not from God, nor does He approve of it. It doesn't bring glory to God but instead divides believers into “them” and “us” groups, causing division and chaos throughout much of church history.
Any teachings or practices that come to the assembly need to be tested by the holy scriptures and proven to be according to the will of God. Authority for statements made about the Bible and in the Bible must come from “holy men of God” who wrote under the guidance and control of the Holy Spirit. It will always be for edification, exhortation, and comfort of the saints of God when it comes from God. Public reading, public preaching, and the words people write to build up the Lord’s people must be tested by the word of God to be from those who “rightly divide the word of truth,” or “correctly handle the word of God.”