Christianity has historically held to the view that God created all things in the universe out of nothing. For many, this reality can be a threatening prospect since the issue of ultimate authority is directly involved with this historical fact. If God created all of material reality and human beings, then human beings are directly accountable to their maker for their behavior. Since God created us he has the ultimate authority to set the rules for our life and how we are to live in his creation. God is the ultimate law maker and since we are the product of his creative work. We are to look to him for the principles by which we are to live.
For people who wish to live their lives according to their own set of ethics, the creation history can be very threatening since it leaves them morally accountable to their creator. Intuitively we all know we are too complex to have been a product of evolution since Romans teaches that God has created us with the understanding that there is a creator. The creation provides sufficient evidence that God exists and will hold us all accountable based on that understanding.
The following link discusses this issue in more detail.