We fear when we encounter something we cannot control. We fear when we face the prospect of losing something we love or experiencing something bad. We even fear when we face the prospect of gaining something wonderful, when that things seems too impossibly wonderful for us. Driling to the bottom of the matter, the Dutch theologian Wilhelmus a Brackel explained that “fear issues forth from love.” That is we fear because we love: we love ourselves and so fear bad things happening to us; we love our families, our friends, our things and so fear losing them.
From the book "Rejoice and Tremble"