I've emboldened the part that I think is wonderfully said!
I've felt the same way for many years. It's absolutely incredible that something spoken so simply can be completely distorted in order to create a new theology, a new eschatology!
For many centuries good Christians read 2 Thessalonians and *never* read "apostasia" as the Departure of the Church from the earth in a Pretribulational Rapture! You have to wonder how effective the Holy Spirit is if He can't even communicate to the Church what Paul meant for 1800 years!
And why so suddenly John N. Darby is privileged to see what few have seen before, to initiate a brand new eschatology in Christian history. It makes one wonder!
I've found it fascinating, and recognize that theology is either a revelation or a bondage. And if the error is a bondage, it is not easily exposed, even if it seems simple to you or me.
Those who hold to a Pretribulation eschatology are, I believe, in a kind of bondage. They are utterly unable to see things from another point of view. So it requires kindness, prayer, and persistence in speaking the truth. Thank you for what you're doing. As peripheral as this topic is to more important topics like Salvation, it is still a part of God's word. And Paul considered it important enough to write this letter.
The real danger is that there are religious movements that get proud and begin to declare themselves the voice of God or the move of God on earth, assuming an attitude that they are the advancement of God's Kingdom on earth presently in some almost militant kind of form. Zealotry and battling with carnal weapons to achieve spiritual fulfillment is not God's Kingdom, but rather, a false Messiah.
That was Paul's concern, that we would get high on ourselves, and miss the real enemy of our souls. Christ is who we need to look to, because he will defeat the foe in his own time, and not when we choose to declare it.