I cannot tell you how many times I have heard people cite “in the twinkling of an eye” as support for an imminent return of Jesus. I have chalked it up to that adage that if you hear something said over and over again, you begin to believe it, and over time it is reflexive and never given any thought to its actual meaning.
The statement is from 1 Cor 15:51–52:
“Behold, I tell you a mystery; we will not all sleep, but we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet; for the trumpet will sound, and the dead will be raised imperishable, and we will be changed.” (1 Cor 15:51–52)
The context clearly indicates that it is not speaking of a so-called imminent rapture and resurrection or how quickly Jesus will return. Rather, it is simply speaking of how speedily our bodies will change when Jesus does return: “For this perishable must put on the imperishable, and this mortal must put on immortality” (1 Cor 15:53).
It says, “but we will all be changed.” How will we be changed? . . . in the twinkling of an eye. So it is not a when statement but a how statement.