Jesus, with the Temple in view, speaks about the coming of the end. Those who marveled at the building regarded it as enduring and noble. They had evidently forgotten that this was no less than the third sanctuary of the Lord. The Lord rejected Shiloh, the tent of the tabernacle, and cast down the temple of Solomon (Jeremiah 7:12-15). Even the foundation of this temple met with grief, since it was the sin of the fathers which had caused the Lord to cast the first one down (Ezra 3:10-13). Putting trust in the building itself missed the point entirely. This temple also would be pulled down, so that one stone would not be left upon another.
The pericope for the Second Sunday in Advent opens in the middle of this prophecy. The world will be in turmoil and confusion on the great and terrible day of the Lord. These signs will be the breaking of the fixed order of the world at the coming of the Son of Man. The nations will be in emotional distress because they will be perplexed, seeing no way out of what is coming upon the world. They will be gripped in the indecision of fear, because of the roaring of the sea and the waves and the breaking of the world. Everything is breaking forth from its appointed boundaries and casting all into confusion. It was God who set the boundaries of the sea (Genesis 1:9-10), commanding its proud waves to stop at His command (Job 38:8-11). The Lord shut its waves in, no matter how much it rages (Jeremiah 5:22), so that it would no more cover the earth (Psalm 104:8-9). But now the old order is passing. The sea threatens to overwhelm all again, because heaven and earth are passing away.
Fear is the only possible response for the godless. They will faint away as though dead, just as the soldiers did at the tomb of Christ (Matthew 28:4) or John did at the vision of Christ (Revelation 1:17). A sense of dread will overtake them, even before the Son of Man appears, because the heavens will rot away and the skies will roll up like a scroll (Isaiah 34:4). They will try to hide, but in vain, because the great day of the wrath of the Lamb has come (Revelation 6:12-17). All the heavens, which seemed so firm and immovable, will be shaken, and nothing will be left upon anything else.
In that hour, they will see Christ, the Son of Man, returning in power and majesty. As the Son of Man, Jesus has dominion over all heaven and earth (Daniel 7:13-14). He will come on the clouds, because they are under His feet. Just as the sky is depicted under the feet of God (Exodus 24:10), so also is the earth His footstool (Isaiah 66:1). Jesus is exalted above all, and all will see Him in the fullness of His glory.
But, Jesus says, lift up your head. Lift your eyes to the hills. The Lord comes as Your Helper (Psalm 121:1-2). Though the believer is in the pit, they can look up to find their deliverance in the coming of the Lord. This is why the return of Christ is a joy for the faithful, even though it is a terror for the ungodly. The Lord sets us free from the waterless pit (Zechariah 9:11-12). In the hour that Jesus judges the living and the dead, He will give justice to His elect speedily (Luke 18:7). All the workers of lawlessness will depart, because all will be set right forever. The violent rhetoric of every imprecatory psalm looks toward this glorious hour, when God will remember every injustice done against His people and bring the due reward of the wicked on their heads. We will rejoice in that hour, because the Lord has not forgotten His people.
Jesus then uses a parable to explain His meaning further. A fig tree bears fruit once or twice a year. The first appearing of its fruit comes in late spring and early summer. When this early fruit appears, it is a sign that the heat of the summer is coming near. Likewise, the signs in sky and sea are a herald of the coming end, not the end itself. The coming winter wind will come and shake the stars from the sky like the late figs from the tree (Revelation 6:13). Thus, these early fruits are the signs of the coming wars and persecutions which Jesus said will come before the end (Luke 21:10-11).
This generation, Jesus says, will not pass away before all these things take place. Generation here does not have to refer to a single group of people in the way we typically use it today. It can also have a broader application, as it does in some of the Psalms and elsewhere (Psalm 14:5; 24:6, for example). Jesus may also be referring to the signs which herald the end, which that specific generation certainly saw before the judgment on Jerusalem in 70 A.D.
However, the key point here is that, even though heaven and earth will pass away and be found no more, the Word of the Lord will never pass away. It is the one enduring and everlasting reality, because it is the Word of the living and eternal Lord. Earth and heaven will perish, but God will remain (Psalm 102:26). The heavens will vanish, and the earth will wear out like a garment, but the salvation of our God will be forever (Isaiah 51:6). Do not put your trust in anything of this world, because they belong to God, and God will destroy them with fire (2 Peter 3:7). But put your trust in the Lord, who is our stronghold in trouble. He will never let the righteous fall (Psalm 55:22).
But watch for that day! If we become bogged down in the anxieties and cares of this world, giving into the works of the flesh, that day will catch us like a thief (1 Thessalonians 5:1-4). Drunkenness and anxiety are the works of those who fear the future, who seek refuge in the things of this world. But that day will come like a trap upon all who are alive. Stay awake! Ask the Father in holy prayer to be counted worthy (or to have strength) to escape. Only through asking, that is, only through prayer will we be found worthy, because prayer relies on God alone. We will stand before the Son of Man on that day because we rely on Him for all things. It will be a fearful day to see the fixed order of the world broken before our eyes, but it will be the last violent pangs of a world reborn through Jesus.