Human beings are ruled by spirits but humans must learn to control and rule the spirits. Spirits possess people according to the mental state of the human beings and keep them in the same state until they are rejected and replaced by another. This is an all time phenomena occurring in all humans. Human beings are always under the influence of spirits. Certain situations and circumstances causes the possession of certain type of spirits. Often thinking and talking about bad subjects or bad imaginations even for fun can take serious turns on one who think and talk. All spirits (good and bad) have the dominating character. They can take you to the extent of sacrifice or suicide.
All of your activities, talks and even thoughts determine what kind of spirits you will have for your life. Only these spirits are the reason for the good and bad happening in your life. Generally spirits determine your destiny from your daily activities, talks and thoughts too. All knowledge, skills, emotions, feelings, interests and everything are spirits. Even thoughts are not your own. For example, when you want to take a decision on a subject, one after another they think and you just listen and choose or reject the ideas which they transmit to your mind through your brain in the form of thoughts. A human being during his/her lifetime is living with many spirits which have joined one by one since birth. All human beings are just unprogrammed robots made of flesh, bones, tissues etc., by birth and toys of the spirits for their games.
Your faith cannot fetch you the Zeus himself but it can get you a spirit representing Zeus. It can guide you and help you in time. But everything is subject to good and bad you did in your life.