Revelation 1:7 (NKJV), “Behold, He is coming with clouds, and every eye will see Him, even they who pierced Him. And all the tribes of the earth will mourn because of Him. Even so, Amen.”
First Advent
This could not have happened at the first advent because history proves that every Jew and Gentile did not see Jesus. A few people saw Jesus on the cross and then they and that whole generation died without Revelation 1:7 being fulfilled.
For all to see Jesus, they must be raised from the dead. Jesus will resurrect everyone at His second advent. (See John 5:28-29.)
Second Advent
Revelation 14:14 (NKJV), “Then I looked, and behold, a white cloud, and on the cloud sat One like the Son of Man,…” If you are on the earth, under the cloud, would Jesus be visible?
Joel 2:1-2 (NASB20), “Blow a trumpet in Zion, And sound an alarm on My holy mountain! Let all the inhabitants of the land tremble, For the day of the LORD is coming; Indeed, it is near, A day of darkness and gloom, A day of clouds and thick darkness.” Those of the world will not see his return as they are under the cloud where there is the darkness of trouble. The gloom of despair is growing.
Jesus also cites the nations mourning (Revelation 1:7) as an evidence of His return in Luke 21:25-27 (NKJV), “…on the earth distress of nations, with perplexity, …men’s hearts failing them from fear and the expectation of those things which are coming on the earth, …Then they will see the Son of Man coming in a cloud (same clouds as in Joel 2) with power and great glory.”
How does every eye see Him then? It is through our understanding or insight that we come to recognize the events that are the evidences of our Lord’s return. The Apostle James said when Christ returns, He will rebuild the Jewish nation. Acts 15:16-17 (NASB20) “… I will return, and I will rebuild the fallen tabernacle of David, and I will rebuild its ruins, and I will restore it, so that the rest of mankind may seek the LORD…” Are we not “seeing” Israel being restored?
The signs of Jesus’s return are clear for all who have eyes to see now. But in the future, all will recognize our Lord’s return.