Furio,
as much as I don't want to sound like a religious science seminar...... The power is within you. God changes your life only through your own mind. For how else can anything be brought upon you, but through mind? Now, about the devil.... Ask yourself this, what power does the devil have? If you are to realize that God is The Only Power, then the answer is, none. The worst idea that is believed by many is the one that says that God has an opponent. If God had an opponent, (this opponent would have to hold power of his own to be worthy of the term), God wouldn't be all-powerful. Hence, if the devil has no true power, then he has no power over you. Never did, never will. The "power" of the devil is an illusion. I cannot stress this enough. God, the absolute, sends no one to hell. We put ourselves through hell, and that seems to be what you are doing right now. Try to understand that there are people in similar situations as you, and some even worse, who have a great faith in life even through rough times. It is hard to see in such a state as you seem to be in, I have been there. The answers are always right there. When you no longer see evil you will no longer experience it. The less you conceive of suffering, the less you will endure suffering. This is obvious truth. That is how 2 men can be in the same situations and one be miserable and the other happy. There is absolutely no law that says you must suffer. Try to be understanding of your fellow humans. Believe that they are doing the best they can with what they have and try to help them. Know that there is only love, not hate. Hate is merely a "blockage" of love. It is not an opponent to God's divine love. Look at all that you have endured in your life. And see yourself now! See the very life within and without yourself. You have made it very far. It is on the verge of destruction when some of the greatest spiritual awakenings occur. Have faith, my friend, you have no need to worry about anything..........