Mere Christianity -- Book 2, Chap. 2
The Invasion

Like atheism, "Christianity - and - water" is too simple -- watered-down version of Christianity.

This is the belief that God is good and everything is all right and there is no talk of sin, hell, devil, redemption -- Unitarianism, universalism, liberalism.  But "mere" Christianity is not a simple religion.

Rather, Christianity has a certain "oddness" about it that rings true about reality.  This is one of the reasons that Lewis embraced Christianity.  It is a religion that you could not have made up or guessed. 

It's "oddness" is found in both the problem it addresses and the answer.

On the one hand, the universe contains much that is bad and meaningless.
On the other hand, the universe contains creatures who know that it is bad and meaningless.

There are only two views of reality that make sense of both of these facts:

1.  Christians -- good world that went bad and yet we still know the good.
2.  Dualism -- good and bad are 2 equal powers that control all of life.

But Dualism, while certainly true to some degree, has another problem:  What do we mean when we say that one is a "good" power and one is a "bad" power?

1.  The minute we say one is wrong and one is right, you are actually appealing to a third thing:  a standard or rule of right or wrong that is beyond the two powers, by which they must be measured. 

2.  Also, evil/bad does not desire evil for evil's sake.  No one likes bad, simply because it is bad.  People do bad things for a greater desire that is usually good.  In other words, the bad results in wanting good things in the wrong way.  "Wickedness" -- the pursuit of some good in the wrong way.  Even "cruelty" is done for a greater desire -- money, power, pleasure, safety, etc.  But good power can desire good for goodness sake, even if not pleasurable.  So bad power actually defeats itself.  Badness is spoiled goodness.  The bad must have the good in order to corrupt it.  So it is either part of the good power or made by some power beyond the good.

3.  Finally, to be bad, the bad power must have attributes of the good -- it must exist, have intelligence and a will -- the bad therefore, must borrow from the good.  Evil is a parasite that lives off of the good, it is not the original thing.

Duality is right to some degree -- there is a duality in creation but they are not equals.  There is an evil power that was once created good and fell.  This world is a battlefield which is occupied by the enemy.  The Christian is called to be a part of a great campaign of sabotage.

The church is the place where we are listening in on the secret line between friends in battle.  That's why the enemy does not want us to be there.  There is a real devil who seeks to destroy and devour us.