"I in them, and they in Me."--John xvii. 23.
The union of believers with the Mediator, of all matters of faith the most tender, is invisible, imperceptible to the senses, and unfathomable; it escapes all inward vision; it refuses to be dissected or to be made objective by any representation; in the fullest sense of the word it is mystical--unio mystica, as Calvin, after the example of the early Church, called it.
And yet, however mysterious, no man is at liberty to interpret it according to his own notions; in fact, there is need of great vigilance lest under the pious appearance of this mystic love injurious contraband be smuggled into the divine sanctuary. We have therefore raised our voice against the false representations of former mystical sects, and of the Ethical theorists of the present time.
Let us first explain the Ethical teaching on this point.
Their belief starts from the antithesis existing between God and man. God is the Creator, man is a creature. God is infinite, man finite. God dwells in the eternal, and man lives in the temporal. God is holy, and man is unholy; etc. So long as these contrasts exist, so they teach, there can be no unity, no reconciliation, no harmony. And as the pantheistic philosophy used to talk about three stages through which life must run its course--first, that of proposition (thesis), then that of contrast (antithesis), and lastly, that of reconciliation, combination (synthesis)--so the Ethicals teach that between God and man there exist these three: thesis, antithesis, and synthesis.
In the first place, there is God. This is the thesis, the proposition. Opposed to this thesis in God, the antithesis, contrast, appears in man. And this thesis and antithesis find their reconciliation, synthesis, in the Mediator, who is at once finite and infinite, burdened with our guilt and holy, temporal, and eternal.
It is only recently that we quoted the following sentence
from 
Professor Gunning's little book, "The Mediator
between God and Man" (page 28): "Jesus Christ is the Mediator equally between
the Jews and the Gentiles; and also between all things that need reconciliation
and mediation; as between God and man, spirit and body, heaven and earth, time
and eternity."
This representation contains the fundamental error of the Ethical theology. It interferes with the boundaries which God has set. It effaces them. It causes all contrasts finally to disappear. And by this very thing, without intending it, it becomes the instrument of spreading the pantheism of the philosophic, school. Not understanding this system, one may be deeply in love with it. This pantheistic ferment is deeply seated in our sinful hearts. The waters of pantheism are sweet, their religious flavor is peculiarly pleasant. There is spiritual intoxication in this cup, and once inebriated the soul has lost its desire for the sober clearness of the divine Word. To escape from the witchery of these pantheistic charms, one needs to be aroused by bitter experience. And once awakened, the soul is alarmed at the fearful danger to which this siren had exposed it.
No; the contrast between God and man must not cease; the contrast between heaven and earth may not be placed upon the same line with that of Jew and Gentile; the contrast between the infinite and finite must not be effaced by the Mediator; time and eternity must not be made identical. There must be brought about a reconciliation for the sinner. That is all, and no more. "To bring about reconciliation" is the work assigned to the Mediator, and that alone. And this reconciliation is not between time and eternity, the finite and the infinite, but exclusively between a sinful creature and a holy Creator. It is a reconciliation that could not have occurred if man had not fallen, necessitated only by his fall; a reconciliation not essential to the being of Christ, but His per accidens, i.e., by something independent of His being.
And since the essence of true godliness is based not in the removal of the divinely appointed boundaries and contrasts, but in a deep reverence for the same; and on this ground the creature as distinguished from the Creator may not feel himself one with, but absolutely distinct from Him, it is clear that this error of the Ethicals affects the essence of godliness.
The early Church discovered this same principle in Origen,
and 
subsequently in Eutychus; and our fathers of the last century found it in the
Hernhutters and sharply opposed it. And only because we lack knowledge and
penetration have these Ethical doctrines been able to spread so rapidly here,
in Germany, in Switzerland and even in Scotland, their pantheistic tendencies
undetected.
And how does this evil affect their Christology? It affects it to such extent that it is entirely different from that of the Reformed churches. Tho they tell us; "We disagree in our views on the Scriptures, but agree in our confession of Christ," yet this is absolutely untrue. Their Christ is not the Christ of the Reformed churches. Christ, as the Reformed Church according to the Scripture and the orthodox Church of all ages confesses Him, is the Son of God, eternal Partaker of the divine nature, who in time, in addition to the divine nature, adopted the human nature, uniting these two natures in the unity of one person. He unites them in such a way, however, that these natures continue each by itself, do not blend, and do not communicate the attributes of the one to the other. Hence two natures are united most intimately in the unity of one person, but continuing to the end, and even now in heaven, to be two natures each with its own peculiar properties. "He is one not by conversion ofthe Godhead into flesh, but by taking of, the manhood into God" (Confession of Athanasius, article 35). And again: "He is one not by mixture of substance, but by unity of person" (article 36).
In like manner do we confess in article 19 of our Confession: "We believe that by this conception the person of the Son is inseparably united and connected with the human nature; so that there are not two Sons of God, nor two persons, but two natures united in one single person; yet each nature retains its own distinct properties. As then the divine nature has always remained uncreated, without beginning of days or end of life, filling heaven and earth; so also hath the human nature not lost its properties, but remained a creature, having beginning of days, being a finite nature, and retaining all the properties of a real body. And tho He hath by His Resurrection given immortality to the same, nevertheless He hath not changed the reality of His human nature; forasmuch as our salvation and resurrection also depend on the reality of His body. But these two natures were so closely united in one person that they were not separated even by His death:"
This clear confession, which the orthodox Church has always 
defended against the Butychians and Monothelites, and which our Reformed
churches in particular have maintained in opposition to the Lutherans and
Mystics, is opposed by the Ethical view all along the line. The late Prof.
Chantepie de la Saussaye said distinctly in his Inaugural that it was
impossible to maintain the, old representation on this point, which was also
upheld by our Confession: and that his confession of the Mediator was another.
Hence the Ethical wing deviates from the old paths not only in the matter of
the Scripture, but also in the confession of the person of the Redeemer. It teaches
what the Reformed churches have always denied, and denies what the
Reformed churches have always maintained in opposition to churches less correct
in their views.
Under the influence which Schleiermacher's training among the Moravian brethren, and his pantheistic development and Lutheran dogmatics, have exerted upon the Ethicals, a Christ is preached by them who is not the Christ to whom the orthodox Church of all ages has bowed the knee; and whose confession has always been preserved incorrupt by the Reformed, and especially by our national, theologians. For their conclusions are as follows:
1st. That the Incarnation of the Son of God would have taken place even if Adam had not sinned.
2d. That He is Mediator not only between the sinner and the holy God, but also between the finite and the infinite.
3d. That the two natures mix together, and communicate their attributes to each other in such a measure that from Him, who is both God and man, there proceeds that which is divine-human.
4th. That this divine-human nature is communicated to believers also.
This error is immediately recognized by the use of the word divine-human. Not that we condemn its use in every instance. On the contrary, when it refers not to the natures, but to the person, its use is legitimate, for in the one person the two natures are inseparably united. Still it is better in our days to be chary of the word. Divine-human has in the present time a pantheistic meaning, denoting that the contrast existing between God and man did not exist in Jesus, but that in Him the antithesis of the divine and the human was not found.
And this is wholly anti-Scriptural, and results in its final
consequences in a pure theosophy. For the actual result is a blending of the
two natures: a divine nature in God. a human nature in 
man, and a
divine-human nature in the Mediator. So that if man had not fallen, the
Mediator would nevertheless have appeared in a divine-human nature.
This is a truly abhorrent doctrine. It puts in the place of the Savior from our sins another and entirely different person; the contrasts between the Creator and the creature disappear; the divine-human nature of the Christ is actually placed above the divine nature itself. For the Mediator in the divine-human nature, possesses something that is lacking in the divine nature, viz., its reconciliation with the human.
This shows how much further the Ethicals have departed from the pure confession of the Lord Jesus Christ than is generally believed. According to them there is in the Person of the Mediator a kind of new nature, a kind of third nature, a kind of higher nature, whichis called "human-divine." And the union with Christ is found (not subjectively, but objectively) in the fact that the Lord Jesus Christ pours into us that new, third, higher kind, viz., the divine-human nature. Hence the regenerate are the persons who have received this new, third, higher kind of nature. This has no connection with sin, but would have appeared even in the absence of sin. The reconciliation of sinners is something additional, and does not touch the root of the matter.
The real and principal thing is, that the Mediator between the "finite and the infinite" (to use the very words of Professor Gunning) imparts unto us, who have the lower, human nature, this new, third, higher, divine-human nature.
Not that the human nature is to be removed, and the divine-human nature take its place. No, indeed; but, according to the Ethical theologians, the human nature is originally intended and destined to be thus ennobled, refined, and exalted. As the slip of a plant, under the influence of the sun, develops and produces by and by choice flowers, so does the human nature develop and unfold itself under the influence of the Sun of Righteousness into, this higher nature.
That this must be accomplished by means of regeneration is on account of sin. If there had been no fall in Paradise, and no sin after the fall, there would have been no regeneration, and our nature's lower degree would have passed over spontaneously into that higher, divine-human nature. And this is, in the circles of the Ethicals, the basis of that much-lauded unio mystica with the Christ.
The invisible church is, according to their view, that, circle, of men into whom this higher and nobler tincture of life has been instilled, and others not so favored still stand without. Hence their lack of appreciation of the visible churches; for does not the divine-human tincture of life determine this circle of itself? Hence their preference for the "unconscious"; conscious confession and expression of thought is immaterial; the principal thing is to be endowed with this new, higher, more refined, divine-human nature. This explains their generally lofty bearing toward men not sharing their opinions. They belong to a sort of spiritual aristocracy; they are of nobler descent, acquainted with more refined forms, living a higher life, from which with pitying eyes they look down upon those who do not dream their dreams of the higher life-tincture.
Let it suffice here only to say that the Reformed churches can not indorse this representation of the unio mystica, but must positively reject it.