Life is said to have originated on Earth (not sure about other places).

Science tells us this happened about four billion years ago. Human life a lot later.

The main theories are that life was created by a creator or natural random events.

Life is a continuous process that once stopped, will not re-start. It can only come from previous life.

In this case I only consider human life. Many of the concepts apply to other organisms as well.

Life seems to be it's own reason for being. The reason for life seems to be to perpetuate life.