Shared ground
Paul presents a moral-and-spiritual chain of cause and result. People refuse “the truth” and prefer what is wrong; then God “sends” an error-producing influence; they come to believe “the lie”; and the stated endpoint is judgment (vv. 11–12). The text ties belief and desire together: not believing truth goes with “taking pleasure in unrighteousness,” and both describe the same group.
The passage also assumes deception is not just an intellectual mistake. It is connected to what people welcome and approve. In that sense, judgment is not shown as arbitrary but as consistent with the direction people have already chosen.
Where interpretation differs
1) How God’s “sending” relates to human responsibility.
Some read v.11 as God actively handing people over to deception as a response to their prior refusal, so the delusion is both judgment and confirmation of their chosen path. Others stress that God’s role can be understood as permitting deception to run its course rather than directly producing it, while still holding people responsible for refusing truth.
2) What “the lie” refers to.
Some interpret “the lie” as a specific end-time false claim tied to the lawless figure in the surrounding context (2 Thessalonians 2:3–10). Others take it more broadly as embracing falsehood in place of God’s truth—an overall posture rather than one slogan.
3) What “all” covers.
Some take “all” as every individual within the described group (“those who didn’t believe the truth”). Others hear it as a more absolute statement about everyone involved in that deception. The immediate wording defines the “all” by their response to truth and wrongdoing (v.12).
Why the disagreement exists
The key verbs are strong (“God sends,” “so that they believe”), and the passage is brief. That leaves questions about how divine action and human refusal fit together, and whether Paul is pointing to one concrete false message or describing the general dynamics of deception. The surrounding context about “lawlessness” and “deception” pushes readers to connect details beyond vv.11–12, but the verses themselves do not spell out every mechanism.
What this passage clearly contributes
Explicitly, Paul says judgment follows refusal because (1) people do not believe the truth (truth), (2) they delight in unrighteousness, and (3) God responds by sending an error-working influence that results in believing “the lie” (vv.11–12). Theological inference, consistent with the text’s logic, is that judgment is portrayed as fitting and coherent: it matches both what people love (unrighteousness) and what they accept (falsehood), and it culminates rather than interrupts that trajectory.