And when [Jesus] had stepped out of the boat, immediately a man out of the tombs with an unclean spirit met him. He lived among the tombs; and no one could restrain him any more, even with a chain; for he had often been restrained with shackles and chains, but the chains he wrenched apart, and the shackles he broke in pieces; and no one had the strength to subdue him. Night and day among the tombs and on the mountains he was always howling and bruising himself with stones (Mark 5:2-5).
The opening line of Faith and Theology's reflection on Macbeth asks:
What if nightmares, and not the waking world, were real?
That is the world of the Gerasene Demoniac. Day after day of nightmares, in which "the truth of human nature were seen not in love but in madness".
But let the frame of things disjoint, both the worlds suffer,
Ere we will eat our meal in fear, and sleep
In the affliction of these terrible dreams
That shake us nightly. Better be with the dead,
Whom we, to gain our peace, have sent to peace,
Than on the torture of the mind to lie
In restless ecstasy (Act 3, Scene 2).
Faith and Theology judges Macbeth against a reading of Thomas' understanding of evil as the privation of the good:
Macbeth is not a Christian play. Christianity understands evil as a privation of the good. Macbeth is about positive evil. Its theme is murder as a manifestation of positive evil. In the play, evil exists. It extends itself. It grows. It devours the good. It has a horrible “generative” quality (as LaCouter nicely puts it in the same review). It is not like ordinary darkness – a privation of light – but like a vacuum that can suck the light out of a room, leaving the human heart blinded and confused.
And yet, for the Gerasene Demoniac, this is all too reasonable, too civilized, too rational. "He was always howling and bruising himself with stones." The good of a life was devoured amongst those tombs in the mountains. By a devouring, growing evil.
Come, you spirits
That tend on mortal thoughts, unsex me here,
And fill me from the crown to the toe top-full
Of direst cruelty! make thick my blood;
Stop up the access and passage to remorse,
That no compunctious visitings of nature
Shake my fell purpose, nor keep peace between
The effect and it! Come to my woman's breasts,
And take my milk for gall, you murdering ministers,
Wherever in your sightless substances
You wait on nature's mischief! Come, thick night,
And pall thee in the dunnest smoke of hell (Act 1, Scene 5).
As Thomas tells us:
The Apostle says: "Our wrestling is not against flesh and blood; but against Principalities and Powers, against the rulers of the world of this darkness, against the spirits of wickedness in the high places" ... The assault itself is due to the malice of the demons, who through envy endeavor to hinder man's progress; and through pride usurp a semblance of Divine power, by deputing certain ministers to assail man, as the angels of God in their various offices minister to man's salvation ...
Although a demon cannot change the will, yet, as stated above (Question 111, Article 3), he can change the inferior powers of man, in a certain degree: by which powers, though the will cannot be forced, it can nevertheless be inclined (Summa I, 114.1&2).
Macbeth embodies the overturning of the rejection of the Evil One promised at Baptism:
Dost thou, in the name of this Child, renounce the devil and all his works, the vain pomp and glory of the world, with all covetous desires of the same, and the carnal desires of the flesh, so that thou wilt not follow nor be led by them?
I renounce them all (BCP 1662, The Ministration of Public Baptism of Infants).
Overturning this rejection we join the Gerasene Demoniac, in a nightmarish world of fears, lies, self-destructiveness, disintegration and darkness.
Our petty jealousies, our lusts, our hatreds, those little acts of malice, our addictions, our greed, they share in that nightmarish world of deceit. They mar the image of the Triune God within us, they blind us to this image in others. They embrace the lie, that this world is not God's, that our common life is not shot through with grace, beauty, truth, love.
Angels are bright still, though the brightest fell.Though all things foul would wear the brows of grace,
Yet grace must still look so (Act 4, Scene 3).
Grace can be discerned even in the darkness. The tragedy of Macbeth is the sobering reality that the destructive darkness can be preferred to the healing Light.
Then people came to see what it was that had happened. They came to Jesus and saw the demoniac sitting there, clothed and in his right mind, the very man who had had the legion; and they were afraid. Those who had seen what had happened to the demoniac and to the swine reported it. Then they began to beg Jesus to leave their neighbourhood (Mark 5:14-17).
A Christian play? It's a part of the drama, not the full play. For that we look elsewhere.
... he was delivered to voluntary suffering,
in order to dissolve death,
and break the chains of the devil,
and tread down hell,
and bring the just to the light (from the Anaphora of Hippolytus).