This passage addresses the coming of the lawless one, the deception that will accompany his arrival, and the ultimate judgment that befalls those who reject the truth.
Paul writes to comfort the believers in Thessalonica who had been deceived to think they were in the Day of the Lord. He comforts them by explaining the prophetic sequence that will precede the day of the Lord and assures them that history is unfolding under God’s sovereign control.
You’ll remember at the end of chapter 23, Saul was hunting David and was nearly ready to catch him, but God sent the Philistines to invade the land and distract Saul. Saul left David to deal with the Philistines. It was all the sovereign work of the Lord. And in Chapter 24 we see God’s sovereignty at work again. Once Saul had dealt with the Philistines, he was told that David was in the Wilderness of En Gedi.