Shared from Mike’s Place on the Web, a snippet, excellent piece!
The very tiny Greek word, en, is used a lot in Scripture, especially in relation to the Second Coming of Jesus Christ. It means “at,” and yet it means a little more than just “at.” It has to do with a fixed point in space and time. Certain things will happen “at” the Second Coming. Or, more accurately, our Lord’s much-anticipated Second Coming will trigger a series of events that will happen. They can’t happen any time before He returns, but they will happen “at” His return. His return is the fixed point in space and time when these events will occur.
Let’s take a quick survey of all the “at’s” of the Second Coming.
Resurrection at His coming
But every man in his own order: Christ the firstfruits; afterward they that are Christ’s at his coming. (1 Corinthians 15:23 KJV)
This verse comes in the midst of Paul’s letter to the Corinthians, in which he was addressing one of many problems this great, metropolitan church had. The good folks in this congregation were worried about the resurrection – whether or not there would even be one. The resurrection was then as it is now, a key part of the Gospel – Christ’s resurrection and our eventual resurrection. Some in the church wondered about it.
Now if Christ be preached that he rose from the dead, how say some among you that there is no resurrection of the dead? But if there be no resurrection of the dead, then is Christ not risen: And if Christ be not risen, then is our preaching vain, and your faith is also vain. (1 Corinthians 15:12 – 14 KJV..
Source: The “At’s” of the Second Coming