Albert Barnes Commentary Acts 10:42

"And he charged us to preach unto the people, and to testify that this is he who is ordained of God [to be] the Judge of the living and the dead." — Acts 10:42 (ASV)

And he commanded us, etc. Matthew 28:19–20; Mark 16:15–16.

And to testify. To bear witness.

That it is he (see the notes on John 5:22-27).

Compare the references in the margin.

Of quick. The living.

The doctrine of the New Testament is that those who are alive when the Lord Jesus shall return to judge the world shall be caught up in vast numbers like clouds to meet him in the air, without seeing death (1 Thessalonians 4:16–17).

Yet before this, they shall experience such a change in their bodies as shall fit them for the judgment and for their eternal residence—a change which shall liken them to those who have died and have been raised from the dead.

What this change will be, speculation may imagine, but the Bible has not revealed it. See 1 Corinthians 15:52: The dead shall be raised, and we shall be changed.