Albert Barnes on 1 Corinthians 15:53

For this corruptible, etc. It is necessary that a change should take place, either by dying and then being raised, or by being changed without seeing death; for we cannot enter heaven as we are now.

Must put on. The word here used (ενδυνω) properly means, to go in, to envelope, to put on as a garment; and then to put on anything; as the soul is, as it were, clothed with, or invested with a body; and here it means, must be endued with, or furnished with. It is equivalent to saying that this corruptible must become incorruptible, and this mortal must become immortal. We must cease to be corruptible and mortal, and must become incorruptible and immortal. The righteous who remain till the coming of Christ, shall be at once changed, and invested, as Enoch and Elijah were, with incorruption and immortality.

(d) "must put on" 2Cor 5:4