Energy has existed as long as the universe has existed. Due to the law of conservation of energy and the law of conservation of matter, there is always the same amount of energy and matter in the universe. That being said, sometimes matter turns into energy and it is also safe to assume that energy can turn into matter.
Energy is the fuel of life. And probably has much to do with what many call souls. There is no part of the brain that we know of where the consciousness is contained, and there are records of people's consciousness leaving their bodies and seeing themselves and others while they were technically dead. Since the 'soul' has no matter, and the only forms in the universe are energy and matter, it is safe to say that our souls would be in the form of energy.
Our bodies produce energy from almost nothing. Our liver does the work of several nuclear plants. We are an incredibly complicated form that somehow finds the ability to run itself until we, for some reason, die. Perhaps the fuel is gone, perhaps the spirit is tired, perhaps the matter of the body simply cannot hold the spirit any longer.
You have always existed, and I have always existed. We were born in the stars, energy and matter pushing together to eventually for the elements through billions of years to what we are today. But life is not some joyride that we sign up for. It is simply the status of the energy and matter that happen to make up our individuality today. When we die, it will be dispersed into the universe and will likely come back again in full or partial form as another being, human or not.
We are God. God is our projection upon this energy and is only there because we want him/her to be. Worship God if it pleases you. Deny God if this pleases you as well. It will not matter because God does not care. God does not have the ability to care unless he does in your mind. And then God will only care because you are God.