(1 Thess. 1:1 ESV) Paul, Silvanus, and Timothy, To the church of the Thessalonians in God the Father and the Lord Jesus Christ: Grace to you and peace.
Silvanus is a longer form of the name Silas, who traveled with Paul. More precisely, “Silas” is a Jewish name and “Silvanus” is Latin. Silas was likely given parallel Jewish and Roman names by his parents, to facilitate dealing with the Gentiles, just as many in the US of Japanese or Chinese origin adopt an American name similar to their native name.
Although Paul speaks of the church in Thessalonika as a single “church” in v. 1, he later writes,
(1 Th 5:27 ESV) I put you under oath before the Lord to have this letter read to all the brothers.
If the church met in a single location, they couldn’t help but read the letter to all the members. Therefore, it seems probable that the Thessalonian congregation was a single congregation under a single leadership but meeting in multiple houses. The letter thus would have been circulated among the houses to be read aloud until the entire congregation had heard it.
Although the Greeks were a literate people, the ability to read the written word was likely limited to about 10% of the population. In fact, Paul’s original letter (the “autograph”) would have been written in all caps, without paragraphs or punctuation, with no spaces, rather like this: INTHEBEGINNINGGODCREATEDTHEHEAVENSANDTHEEARTH. Paper was so expensive that it made sense to run the words together to reduce the cost!
Therefore, it’s likely that whoever carried the letter from Paul to the church — an individual traveler, not the postal service — read the letter to the church, as the courier would know what Paul intended and could answer questions and offer explanations where helpful.
That is, the epistles were rather like “briefs” in the British legal system. In the American courts, the long-form of the arguments are made in the briefs, while oral argument is generally a shortened version of the legal arguments, to help acquaint the judges with the case. But in England, the briefs are brief and the full arguments are the oral arguments.
Therefore, it’s not surprising that Paul’s language is often very compressed and dense. He was writing a British-style brief, expecting his emissary to expand on the discussion through questions and answers.
Paul, as was his custom, combines his references to God and Jesus: “in God the Father and the Lord Jesus Christ” surely because he saw the two as inseparable.
“Grace and peace” combines the customary Greek and Jewish salutations with a modification, changing chairein (‘greeting’) to charis (‘grace’). “Peace” is, of course, the Jewish salutation “shalom.” We might better translate “grace and shalom” understanding that both terms carry great theological weight with Paul as both result from getting into right relationship with God and Jesus.
Paul refers to Jesus as “the Lord Jesus Christ.” “Christ” means “anointed one” and might be better translated “Messiah” or “King.” “King” would be accurate but the word in English fails to pick up the prophetic significance of this particular king, the Messiah.
“Lord” is the word used in the Septuagint (LXX) to refer to the Hebrew YHWH. To call Jesus “Lord” was to refer to him as God — not the same person as God the Father but somehow inseparable from and one with God. (This is not the time or place to work out a full Trinitarian theology.)
“Lord” is also a title used to refer to the Caesar (likely Claudius at this time). Therefore, subtly, Paul is saying, “Your true Lord is Jesus, the Messiah, not Claudius.”