he was lifted up, and a cloud took him from their sight.
While they were looking intently at the sky as he was going,
suddenly two men dressed in white garments stood beside them.
They said, "Men of Galilee,
why are you standing there looking at the sky?
This Jesus who has been taken up from you into heaven
will return in the same way as you have seen him going into heaven."
-- Acts 1:1-11
Since the Ascension Christ's coming in glory has been imminent, even though "it is not for you to know times or seasons which the Father has fixed by his own authority.". This eschatological coming could be accomplished at any moment, even if both it and the final trial that will precede it are "delayed".
-- CCC 673