No one can predict the future, of course although it is reasonable to assume that in some ways life probably will be easier in half a century, given our present rate of technological and medical advances.
But the Bible tells us that some things never change, no matter how advanced or sophisticated we are. For example, God never changes and He will be just the same half a century from now as He is today: all-powerful, all-loving, all-just, all-knowing and so forth.
"I the Lord do not change" (Malachi 3:6).
Nor does human nature change. Yes, we may grow better educated or more skilled, but down inside we are still sinners, and we still have the capacity for both great good and great evil. I wish I could promise you that the world will be at peace half a century from now but I can't, because human greed and hatred and jealousy will still be with us. As the Bible says, "There is no one righteous, not even one" (Romans 3:10).
But one thing will not change and that is Christ's power to forgive and to change our hearts from within. Don't allow yourself to be consumed with worry about the world your grandson may face, but pray for him, that the day will come when he gives his life to Christ and discovers in Him the strength he will need to meet life's challenges, no matter what they may be.