One of the popular tenets within the Christian religions is that a rapture will occur without warning and whisk all the born-again Christians up to heaven just before tribulations begin to occur to the unfortunates remaining here on earth. The Left Behind series by Tim LaHay and Jerry B Jenkins dramatized the rapture in about a dozen books, and people gobbled them up as soon as each book was released--me included.
The belief is based on Matthew 24:21-31, 1 Corinthians 15:52, 1 Thessalonians 4:16-17, and Revelation 1:7, to name a few. I'm not copying them into this because it would be too long. You can look them up in your own Bible or just Google them online.
I do believe it will happen. When I first started reading about these things back in the 1970s, I was convinced the Rapture would happen any day. Several times since then, folks here and there have decided again that it's going to happen any day. Only God knows the day, though, and not us.
We can't drop everything we're doing in anticipation of something that might not happen in our lifetimes. I don't believe that's what God would have us doing. There's still so much to do! There are still homeless people who need food and shelter, children who need food and schooling, villages that need clean water, souls who need Christ, books still to be written, songs yet to be composed.
Work while the day is here. The Rapture may be around the corner and Jesus's outstretched arms might appear out of the clouds any moment now. Now, do you want Him to catch you hard at your assigned work, or do you want Him to catch you in your rocking chair gazing into the sky? And what is it to you if you keep on a-working until you go meet Him the same ol' way we've been doing it since creation?