Paul wrote to correct the Thessalonian believers who had been deceived about Christ’s return, reminding them that truth brings clarity and protection against false teaching. He warned that deception—whether from false prophets, the “man of lawlessness,” or subtle half-truths—always begins by twisting God’s Word and drawing people away from the truth of Christ. The only defense against deception is to stand firmly on God’s truth through Scripture, discernment by the Holy Spirit, and guidance from mature believers.