This is a tangent, but he correctly translated 2 Thessalonians 2 as "departure". Modern perverts change what he wrote to rebellion or falling away.
I happen to have just listened to a bible study done by Bob Enyart this last Sunday about the Rapture where he made the argument that apostasia should be translated "departure" and I am in the long and well established habit of taking Bob's word for it when it comes to such things and for that reason alone, I do indeed tend to agree that "apostasia" should be translated as "departure".
However!...
Translating apostasia as "falling away" is neither a perversion nor is it modern. Quite the contrary!
You have to go all the way back to the Geneva Bible to find it translated into English as "departure". Since then, from the King James Bible onward, it's been translated as "falling away" or "rebellion" or simply transliterated into "apostasy" and for solid, non-doctrinal, reasons.
For example, every use of apostasia in the Septuagint refers to defection, rebellion, or apostasy in the sense of turning away from God or some other authority. There are no instances in the LXX where it means a physical “departure.”
That fact alone would have heavily shaped how Paul’s Greek speaking audience in Thessalonica understood the term. Unless the context in II Thessalonians 2:3 clearly forced a new sense, the natural reading from both Scripture and contemporary Greek would be rebellion or falling away, not “departure.”
The only other use of the term in the New Testament is Acts 21:21...
Acts 21:21 but they have been informed about you that you teach all the Jews who are among the Gentiles to forsake Moses, saying that they ought not to circumcise their children nor to walk according to the customs.
That usage does not support a physical departure. Rather, it demonstrates that by the New Testament period, apostasia meant a defection or turning away from a person or principle, not a change of physical location.
In short, there are good arguments on both sides. Those who hold to a pre-tribulation rapture are the ones who cling most tightly to translating it as "departure", which is understandable but not necessary for the position to be well established. I'd advise against being dogmatic about it.