Should the Devil come with the God package?

I've read this excellent article on the conversion diary a few months ago, and I've been recently thinking about it when I felt exaggeratedly guilty for small reasons(like not calling a friend for a few weeks). Those feelings put me down, and prevented me from acting, making things even worse..

I've been thinking about Evil. Yes, Evil with a capital letter. What is Evil? Or should the question be : "who is the evil one?" does it exist?
I do believe in God, do I have to believe in the Devil as part of the package?
Why do you sound so ridiculous when you mention any devil, Satan or Evil one in a serious sentence...?

I mean obviously my bad feelings came at a stressful time at home and at work, and I got over it... But what if..?

Once a sister told me, and a bunch of other girls, during an interesting formation that the smartest move of the devil was to make believe he doesn't exist.
Can you fight against something that doesn't exist? It is so difficult to even mention the topic without looking like a crazy paranoiac!

So I took one of my desert island books, it's one of my freedom shields and I'm glad I have it handy!
God, without any idea of evil (the freedom of man in the heart of God), Jean-Michel Guarrigues.


I call it freedom shield because, along with the excellent Humility of God (Fr Varillon), these books explains quite simply the very difficult questions of human freedom in God's plan, and in this specific case, the freedom to chose between good and bad.

Look at this wall painting from fra Angelico, the Mocking of the Christ.
From this, much bible quoting and some references to St Augustin, Fr Garrigues develops a very helpful theology of the innocence of God.
I need to read the book again to give a clearer explanation, and it is quite late right now.. But I need to clear my thoughts, once again...

I do believe there is a struggle for each one to chose between life and death, our being tends to opt for life, but we can be too easily "talked" into death, many little lies can add up to having us buying into great evil. Like abortion. (oops this one slipped out of my fingers, I didn't want to talk about it here).
What I remember most clearly from this book was the commentary of this wall paint, and the last chapter " how does God know the evil if he has no idea of evil?"
that was a good question, and the answer seemed really simple to me, the author answers that God knows the bad as a lack of good, a lack of love. Like when you see the negative of a film...
I don't know why it seemed so obvious the first time I read this book, and now I'm confused.
Freedom is hard work... More in the next episode...