It is a common mistake to think that everything will continue as it always has (2 Peter 3:3-4).  Global warming is slightly shaking that assumption, but many think it will not really make much difference ... and so they continue as before.  But God has the right to do whatever He chooses, and that will include the way the night sky will undergo sudden change, and the sun (on which we depend for so much) will be switched off. Everything we think of as the 'natural world' will not continue on autopilot indefinitely (2 Peter 3:5-7).  When God intervenes, the change will be as radical as His creative masterstrokes in Genesis 1:1-27.

Jesus' words of large-scale cosmic disturbance echo the prophecy of Daniel 7:13-14 and are reflected again in Revelation 19:11-19.  Both are giant passages of Scripture showing the authority and power of God bringing everything to submit to Christ (Ephesians 1:10).  What Jesus said fully validates both prophecies, and is the anchor of hope for the world-wide church and each individual believer (Hebrews 6:19-20). The appearance of Jesus will be joy for the believers and terror for the unbelievers (Revelation 1:7-8).

Not only will the visible creation undergo change, but God's invisible creation (the angels) will have a new task - to bring in the harvest of His own people (Matthew 13:30; 39).  Both the living and the dead in Christ will be brought together to greet the Lord Jesus (1 Thessalonians 4:16-17): as the bridegroom finally comes for His bride, the church (Revelation 19:7).  Coming after such dreadful predictions about the future (Mark 13:11-23), Jesus is explaining the 'hope' of the Christian - certain confidence that, despite whatever may happen, Jesus will come to claim His own (Revelation 22:17) ... and nothing will stop Him!

From the earliest days of the church, the Christian's 'hope', of being welcomed by Jesus when He returns, has been the essential ingredient to survive and thrive in hardship (1 Thessalonians 4:13-18).  Today, more Christians are suffering because of their faith than at any other time in history.  But there will come a day when Jesus returns, and every right-thinking believer looks forward to that day.  As 2 Peter 3:13 says, “But in keeping with his promise we are looking forward to a new heaven and a new earth, where righteousness dwells.”  That hope helps us to keep pressing on in Christ (Philippians 3:12-14) without giving up, whatever the challenges.