Explain the Second Coming

The appearance of Jesus to His disciples was not Jesus’ “second coming” because at that point Jesus had yet to depart the earth. The Bible testifies that at His death, Jesus’ spirit descended into the depths of the earth, into a place called Sheol. Paul says in Ephesians:

Eph. 4:8      Therefore it says, 
    “WHEN HE ASCENDED ON HIGH, 
    HE LED CAPTIVE A HOST OF CAPTIVES, 
    AND HE GAVE GIFTS TO MEN.”
Eph. 4:9 (Now this expression, “He ascended,” what does it mean except that He also had descended into the lower parts of the earth?

And Peter says:

1Pet. 3:18 For Christ also died for sins once for all, the just for the unjust, so that He might bring us to God, having been put to death in the flesh, but made alive in the spirit;
1Pet. 3:19 in which also He went and made proclamation to the spirits now in prison,

After His resurrection, Jesus walked the earth for 40 days making appearances to His disciples to prove His claims. He had not yet left the earth at that time, so these appearances were still part of Jesus’ “First Coming.” As Paul explains:

1Cor. 15:3 For I delivered to you as of first importance what I also received, that Christ died for our sins according to the Scriptures,
1Cor. 15:4 and that He was buried, and that He was raised on the third day according to the Scriptures,
1Cor. 15:5 and that He appeared to Cephas, then to the twelve.
1Cor. 15:6 After that He appeared to more than five hundred brethren at one time, most of whom remain until now, but some have fallen asleep;
1Cor. 15:7 then He appeared to James, then to all the apostles;
1Cor. 15:8 and last of all, as to one untimely born, He appeared to me also.

These series of post-resurrection appearances are part of Jesus’ first time on earth and are not the “second coming” of Jesus. We know this because the Bible says that at Jesus’ departure, angels declared that Jesus will return at His Second Coming with power and glory:

Acts 1:6 So when they had come together, they were asking Him, saying, “Lord, is it at this time You are restoring the kingdom to Israel?”
Acts 1:7 He said to them, “It is not for you to know times or epochs which the Father has fixed by His own authority;
Acts 1:8 but you will receive power when the Holy Spirit has come upon you; and you shall be My witnesses both in Jerusalem, and in all Judea and Samaria, and even to the remotest part of the earth.”
Acts 1:9 And after He had said these things, He was lifted up while they were looking on, and a cloud received Him out of their sight.
Acts 1:10 And as they were gazing intently into the sky while He was going, behold, two men in white clothing stood beside them.
Acts 1:11 They also said, “Men of Galilee, why do you stand looking into the sky? This Jesus, who has been taken up from you into heaven, will come in just the same way as you have watched Him go into heaven.”

Only after Jesus was taken up into Heaven was the first coming of Jesus complete. Now the world awaits His second coming, which will be a moment unlike anyother:

Zech. 14:3 Then the LORD will go forth and fight against those nations, as when He fights on a day of battle.
Zech. 14:4 In that day His feet will stand on the Mount of Olives, which is in front of Jerusalem on the east; and the Mount of Olives will be split in its middle from east to west by a very large valley, so that half of the mountain will move toward the north and the other half toward the south.
Zech. 14:5 You will flee by the valley of My mountains, for the valley of the mountains will reach to Azel; yes, you will flee just as you fled before the earthquake in the days of Uzziah king of Judah. Then the LORD, my God, will come, and all the holy ones with Him!
Zech. 14:6 In that day there will be no light; the luminaries will dwindle.
Zech. 14:7 For it will be a unique day which is known to the LORD, neither day nor night, but it will come about that at evening time there will be light.
Zech. 14:8  And in that day living waters will flow out of Jerusalem, half of them toward the eastern sea and the other half toward the western sea; it will be in summer as well as in winter.
Zech. 14:9  And the LORD will be king over all the earth; in that day the LORD will be the only one, and His name the only one.

Scripture quotations taken from the (NASB®) New American Standard Bible®, Copyright © 1995, 2020 by The Lockman Foundation. Used by permission. All rights reserved. www.lockman.org