What did Paul mean by the mystery of iniquity already working?
Paul meant that the mystery of iniquity—idolatrous rebellion against the true worship of Jehovah—was already actively working. It began when humanity was scattered from the Tower of Babel and has continued as a constant adversary, drawing Israel into idolatry and confronting Paul in the Gentile world.
Les explains that the mystery of iniquity has been working ever since the Tower of Babel. In Genesis, the early post-flood people gathered in the valley of Shinar on the Euphrates and built the Tower, and from there all pagan idolatrous religion began. Every cult and all world religions trace their roots back to Babel. Paul wrote in 2 Thessalonians that this mystery was already working, and it has been a constant adversary of the true worship of Jehovah. For Israel, the nemesis was idolatry like Baal and Moloch. On this side of the cross, Paul went to the Gentile world and was confronted with the same, as in Acts 19.