I believe that many religions will have a different answer to this question depending on their belief, but what does the Bible say? From the beginning we know that God made the earth and mankind to be inhabited and for man to populate and live forever. So we can ask ourselves, did God's plan change or did He get something wrong? Well for those who believe in God and what the Bible says, then we know that He did not get it wrong. Yet so many people believe that the earth will be destroyed and mankind will either go to Heaven or to Hell. The scripture at Ps. 37: 10, 11 shows just one of the references in the Bible where God says that mankind will not be destroyed and it says:
And just a little while longer, and the wicked one will be no more; And you will certainly give attention to his place, and he will not be. 11 But the meek ones themselves will possess the earth, And they will indeed find their exquisite delight in the abundance of peace.
In the book of Matthew, Jesus tells us some of the things that will happened during this great tribulation that is going to occur at the time of the end. Matthew 24:21 was answering a question from Jesus' disciples about sign of his presence. At Matthew 24: 3 - 8, Jesus there is explaining some of the events that will be taking place during HIs presence. In 2 Timothy 3:1 - 5 tells us how the attitudes of mankind will be in the last days of this system of things.
3 But know this, that in the last days critical times hard to deal with will be here. 2 For men will be lovers of themselves, lovers of money, self-assuming, haughty, blasphemers, disobedient to parents, unthankful, disloyal, 3 having no natural affection, not open to any agreement, slanderers, without self-control, fierce, without love of goodness, 4 betrayers, headstrong, puffed up [with pride], lovers of pleasures rather than lovers of God, 5 having a form of godly devotion but proving false to its power; and from these turn away.
Then the book of Revelation really helps us to appreciated the blessings that we have in store for us, one being at Revelation 21: 3, 4 where it says:
. 3 With that I heard a loud voice from the throne say: “Look! The tent of God is with mankind, and he will reside with them, and they will be his peoples. And God himself will be with them. 4 And he will wipe out every tear from their eyes, and death will be no more, neither will mourning nor outcry nor pain be anymore. The former things have passed away.”
These are some areas in the Bible in which help me to have some clarity on what will take place in the near future for mankind, I hope that your personal study of the Bible will help you gain the understanding of what the future holds for you.