No poet possesses such a profound knowledge of the dark side of human life, and none has laid bare its depths to us so strikingly, as Shakespeare. He knows how the stealthy tempter invades the heart, by what struggles he enters in, by what path alone lies salvation, and what inward and outward wretchedness he who knows not how to find this path must endure until he perishes under the sorrows of life; and all the most celebrated and greatest of Shakespeare's dramas bear the inscription in clear characters, 'the wages of sin is death.' . . . But in order not to miss the key to the tragedy of Macbeth, we must, first of all, acknowledge that there is outside the world of man a realm of demons whose dark, secret powers seek to gain an influence over human souls, and do gain it, except so far as they are opposed; and thus it happens that this Satanic band is known and sought after by man, or is unknown and undesired, and its influence is only bewailed without the sufferer's having the strength to withstand its power.
This definite conception and recognition of a spiritual realm, whose influence over human souls is full of malignity, woe and terror, is to be found in all periods of human history, and in all stages of civilization. Evident traces of it have been discovered among the ancient Egyptians at the time of the Pharaohs. It runs through the system of Hindu philosophy, again emerges in the world of antiquity, and is to be discerned throughout all Germanic heathendom, and reappears in the Australian and American races. It would be passing strange if this primitive and universal belief in the existence, and in the secret influence, of an evil, spiritual world were a mere fancy, as modern times would fain have us believe.
In a word, Shakespeare is penetrated with the truth, of which we have proofs over and over again in the Bible, that there is a secret world of evil spirits that with Satanic cunning lie in wait for human souls, conquering the unguarded heart and rejoicing in hurling their victim to the dust in the misery of sin. Under this weight of demoniac influences lies Macbeth when the drama opens, however much he may struggle against it.
There are two points which Shakespeare especially emphasizes for us in the character of Macbeth. Before the deed we mark the insidious approach of the tempter, and the terrible conflict with the powers of darkness, and then after the deed the strength of an evil, unappeased conscience, which in the struggle to assure and to protect itself, advances from one ill deed to another until the edifice of bloody crimes topples headlong with a crash. If we follow up these two phases of the drama, we clearly enough perceive that Macbeth had for a long time fostered his ambition with the thought of his possible possession of the throne, although the bloody path to it may have seemed to him far distant. Moreover, a heavy dream of the murder of the king had lately caused him much anxiety.
In the first scene of the last act Shakespeare shows us how heavy is the weight of an unexpiated crime, and what a failure follows every human soul who enters into an alliance with the powers of darkness. Lady Macbeth seemed to be so steeled against all assaults of an evil conscience, and seemed to wield so complete a power over herself and her bad actions, that she might have bid defiance to all Hell. But over against all her attempts of a proportionate power in evil-doing stands the saying of the Apostle in its full force: 'Be not deceived; God is not mocked.'