Interpreters (including this one) routinely claim that 2 Thess 2 is one of, if not the most difficult and obscure passage that Paul ever wrote, particularly if one is forced to make sense of the “restrainer” passage in vv. 7-8a, about which Augustine famously quipped: “I frankly confess I do not know what he means.” There are also other difficulties in vv. 9-11, not least of which how to make sense of a God who sends people “a powerful delusion, leading them to believe what is false” (v. 11). Thankfully, the Lectionary comes to the rescue and keeps us from having to preach on vv. 6-12! If you sense sarcasm in my words, you are perceptive. I simply do not know how a preacher can preach this text the way the Lectionary has divided it up. For starters, how does one even bring up the “man of lawlessness” in vv. 3-4 without going on to speak about his defeat by the Lord Jesus in his royal coming (v. 8)? As hard as it may be, I think a preacher ought to include all of 2:1-12 when preaching from this section of 2 Thessalonians rather than avoiding its inherent difficulties.
With that said, however, given that there are a number of links between vv. 1-12 and 13-17, the Lectionary is right to suggest that vv. 13-17 are a part of the single literary unit that begins at v. 1. Preaching or teaching the whole passage as one literary unit helps to clarify that the primary purpose of this difficult passage is not to provide a roadmap for the future; it is to comfort or encourage the church (see esp. vv. 16-17) in the face of ongoing suffering and misleading eschatological rumors.
Given the difficulties in the specific details of this literary unit and the limited space available in these reflections, I will not attempt to offer a verse by verse commentary on the verses in the lectionary. If you are looking for that (and I hope you are!), I would refer you to my recently released commentary on 1 & 2 Thessalonians. What follows are more general hermeneutical and theological reflections on the overall gist of 2 Thess 2:3-12. These are the verses in this literary unit that I imagine will present the biggest challenge to most preachers.
Unfortunately, history is littered with interpretations that have used 2 Thess 2:3-12 like a roadmap for the future—a future that almost always happens to overlap with the present day of the interpreter. For example, ever since the second century, some well-meaning preachers have combined the description of “the man of lawlessness/sin” in this text with images from Revelation 13 and certain passages from Daniel to form a picture of “the Antichrist” of “the end times” which, not surprisingly, closely resembles their own current theological or political enemy. To date, all such efforts to interpret this passage as predicting and corresponding to only one particular person in the interpreter’s present have turned out to be sheer speculation that reveals more about the interpreters’ own prejudices than the biblical text itself. Still, these sorts of efforts continue unabated in many evangelical churches (and are often heightened during election season!).
One might say, however, that some of these past attempts at least moved in the right direction by attributing the pattern of idolatrous arrogance found in 2 Thess 2:3-4 to certain individuals and/or institutions in their particular social/historical contexts. There have indeed been various “men of lawlessness/antichrists” down through the centuries, if with that language we mean people or institutions who embody this pattern of idolatrous arrogance that marks them out as completely opposed to the Christ’s lordship and the kingdom of peace and justice into which God calls all Christians.
In vv. 3-11, Paul was warning the first-century church in Thessalonica about just such a person/institution in their specific historical context, but unfortunately, as Augustine also recognized, we know little about the specifics of that particular context. What we do know is that the pattern exemplified by the “man of lawlessness” in vv. 3-4 was embodied by a whole trajectory of arrogant OT kings who opposed God and God’s people (e.g., the King of Tyre in Ezek 28, the King of Babylon in Isa 14). We also know that this pattern has loosely fit numerous other historical individuals who have portrayed themselves as virtually all powerful, even god-like, and have perpetrated horrific violence and injustice, whether locally or on a larger scale. “Man of lawlessness”—indeed, even “Antichrist”—is a fitting name for such people.
But if we are correct to recognize and label such people as “Antichrist,” it will not be because we have carefully read the Left Behind series. It will be because we have paid careful attention to the way Paul and other NT writers have first described Christ himself. In preaching on this text, I would recommend that you have 2 Thess 2:3-12 open on one panel in your Bible software program and Phil 2:5-11 open in another panel. The latter passage is essentially the reversal of the pattern found in the former. In other words, when these two texts are read together, they give the church a revelatory pattern of comparison to help us to recognize what it means to refer to someone or some institution as “Antichrist.”
I conclude these brief reflections by directly quoting the last paragraph of a section from my commentary dealing with Paul’s “Antichristology”:
Perhaps at some point one last “man of lawlessness” will emerge who climactically embodies the pinnacle of human evil and violence and is therefore “exponentially” opposed to Christ’s lordship and kingdom of peace. In that case, this text is very clear as to his final fate, i.e., at Christ’s royal coming to consummate his kingdom of peace, he will destroy this man of lawlessness. In the meantime, in terms of Pauline logic, it is profoundly appropriate to refer to any sort of human figure whose actions bear analogy to that of the man of lawlessness, whether clothed in the royal robes of Tyre or Babylon, clad in Roman imperial dress, or bearing the swastika of the Third Reich, as Antichrist. But as this passage suggests, the lawless one’s exploitative power remains deceptive to those whose imaginations are captive to commonsense cultural categories (2 Thess 2:9). Indeed, as history confirms, not everyone—even, or especially, those committed to some version or other of “Christian” civil religion—may recognize such “men of lawlessness” for what they actually are any more than everyone recognized Jesus for what he actually was. It takes a revelatory pattern of comparison to recognize a singular, public, human face as an instantiation of the power of lawlessness. And that revelatory pattern of comparison is seen nowhere else than the human face of a crucified Jew from Nazareth in which the glory, holiness, and character of God were on display (2 Cor 4:6). It is those whose imaginations have been shaped to recognize true divinity and true kingship in the face of this cruciform Lord who are divinely equipped to recognize their opposite—Antichrist—in the unveiled face of lawlessness.  City of God, 20.19.  1 & 2 Thessalonians, Two Horizons NT Commentary (Grand Rapids: Eerdmans, 2016), 179-206, 271-87.