“Take heart; I have overcome the world.” (John 16:33)
Satan enjoys suffering. But we do not live in a world where Satan has the final say. Jesus has all the power. However bad the situation in this world or in your life becomes, it is never because Jesus is losing. He still is in control. It cannot go further than He allows. We can always cry out to Him, for He is mighty to save.
Whatever we are going through, and whatever may happen to us and to our loved ones here on earth, we know it is not the end. There is a new earth coming. All who have believed in Jesus will be there. Then, God will “wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, nor pain anymore, for the former things have passed away” (Revelation 21:4).
No disease, no sadness, no death will be there. That is our final destination. Therefore: you do not need to be afraid.