The Fourteenth Lord’s Day

14 The Fourteenth Lord’s Day
Matthew 1:20
But while he thought on these things, behold the Angel of the Lord appeared to him in a dream, saying, Joseph, son of David, do not fear to take Mary as your wife; for that which is conceived in her is of the Holy Spirit.
These words contain a reason given by the Angel of the Lord as to why Joseph should receive his wife Mary. And the reason removes the cause for which Joseph might have been induced to put her away from himself. Now the cause was that she appeared to be with child by a man other than her own husband. This cause is removed by putting another unblameable cause in its place; and this cause is determined by the Angel to be the Holy Spirit. The effect then, is placed with its causes in this enunciation. The effect then, is Jesus Christ, as to his human nature. There are two causes: the Holy Spirit, and the Virgin Mary. Mary is the efficient cause, the less principal cause, and also the supplier of the material cause. But the Holy Spirit is the most principal and first cause. He brings the less principal, the efficient, and the material causes together into acting, to produce this effect.1
Doctrine 1. Christ the Son of God took to himself, into the unity of his person, the nature of man truly such, together with the conditions of human weakness.
This is taught in the Text. When it is said, In time a man born and begotten of a woman, it is but the same thing expressed in these words of the Creed: conceived of the Holy Spirit, and born of the Virgin Mary, etc. He might have assumed the nature of another creature, such as an Angel; he might also have assumed man’s nature in its greatest perfection, as Adam was made (who was never perfect, properly speaking), neither conceived nor born an infant. But it was his pleasure to assume the nature of man — truly such, with sinless imperfections — and not of Angels.
Reason 1. That he might do man’s business and work; that is, to make satisfaction for them and save them. 
Reason 2. He would also take our nature in its weak and lowly condition: 
First, because he would come down (as far as it could be without sin) into the same place and condition out of which he intended to lift us up higher. 
Secondly, that by this means he might in some way sanctify all the states and conditions of human life, lest any might imagine that any such low estate separates a man from communion with Christ.
1 Aristotelian logic: (1) A material cause is determined by the material of which the moving or changing things are made; here it is the flesh and blood supplied by Mary. (2) A formalcause is the arrangement, shape, or appearance of the thing; here it is human nature. (3) An efficient or moving cause refers to something apart from the thing itself, which interacts with it so as to be an agency of it; here it is Mary giving birth. (4) A final cause is the aim or purpose being served by it; here it is the effect, which is Jesus Christ. What Ames refers to as the principal or first cause, is the initiating and creative cause; which is the Holy Spirit by whom Jesus is conceived.
Thirdly, that he might leave this to us in his own experience, as a pledge of his knowledge and of his like sufferings and affections with us, from which he might look upon our infirmities.1
Use 1. Of Information: for establishing our Faith in this regard: that we give no place to the fantastic imaginations of Heretics who impugn directly or indirectly, and fight the human nature of Christ, directly or indirectly, and fight against the human nature of Christ. These sorts of errours are in some way countenanced by Papists in their Doctrine of Transubstantiation, and by Ubiquitarians2 in their Doctrine of Consubstantiation, in as much as they attribute omnipresence and other similar divine attributes to the human nature, which in no way agrees with it.
Use 2. Of Exhortation: to extol and to solemnly praise the grace of our Lord Jesus Christ with all admiration and thanksgiving, who not only agrees to become man for us, but also in the nature of man did not disdain to become an infant, to be conceived, and to be born after our manner; and to undergo other similar infirmities and humiliations for our sake. This is what the Apostle points out in Hebrews 2:17-18.3
Use 3. Of Consolation: that we should make no difference between an infant newly conceived or born, and a perfect man or one of age; or between any other conditions of the nature and life of man as to our interest in Christ, as if any sinless condition of nature could make us less regarded by him, or exclude us from him. For Christ descended to the lowest and most imperfect sinless degree and condition of the life of man — in that he was 1. conceived; and 2. enclosed in his mother’s womb the ordinary time of other births; and 3. born. 
Doctrine 2. Christ assumed this human nature from Mary, as from his Mother.
For though he is said in the Text to be conceived in her, yet elsewhere he is said to be made after the flesh of the seed of a woman;4 and a woman is said to have conceived him, and to have born him as her Song of Solomon 5 Hence also he is called the son of Mary,6 the son of David,7 the son of Abraham,8 and the like, whereby that phrase is expounded, and the truth of it is confirmed.
Reason 1. He should have been born of a woman, as he was of his mother, to the end that the first Evangelical promise of the seed of the woman — that he was to tread down the serpent’s head — might be fulfilled. 9
Reason 2. It was right that he was born of Mary, so that it might be certain how he descended from the tribe of Judah, and from the Family of David, according to the prior promises and prophecies about him.
1 Hebrews 4:15 For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin. 
2 Advocates of Luther’s doctrine that Christ’s body is omnipresent, and therefore exists in the Eucharistic bread.
3 Hebrews 2:17-18 Therefore, in all things He had to be made like His brethren, that He might be a merciful and faithful High Priest in things pertaining to God, to make propitiation for the sins of the people. 18 For in that He Himself has suffered, being tempted, He is able to aid those who are tempted.
4 Romans 1:3.
5 Galatians 4:4. 
6 Mark 6:3. 
7 e.g. Matthew 9:27; Matthew 15:22; Matthew 20:30; Matthew 21:9. 
8 Matthew 1:1. 
9 Genesis 3:15.
Use 1. Of Refutation: against Anabaptists and their like who fantastically think that the humanity of Christ only passed through Mary, and was not assumed from her nature. The first reason for such an imagination seems to have been that some simple men could not conceive how anyone could be born of a woman, after the fall, without sin. But though Anabaptists afterwards removed this ground of their errour of denying original sin, yet they adhered to their conclusion of mere willfulness [to sin], without any reason.
Use 2. Of Information: for directing our Faith about Christ’s sonship. For he is the Son of God and the son of man both, yet so as he is not two sons, but in a certain way he is twice one son in one person. The first, from eternity; the next, in time; and consequently he is in two ways a son, as both by eternal generation, and by generation in time. Yet he is but one son of God and of man, because he is but one person who, according to his divine nature is the Son of God, and according to his human nature he is the son of man. So every man is twice a son in essence, first to his father and paternal generation, and then to his mother and maternal generation.
Doctrine 3. Christ was born of Mary, remaining still a virgin after he was born.1 This is gathered from the scope of the words; the question is this: whether Mary was a virgin or not; and the words of the Angel were to assure Joseph that she was. 
Reason 1. That this might be a singular and miraculous sign to the whole house of Israel, and this is what is pointed at in Isaiah 7:14. 
Reason 2. That the prophesies which had gone before about this thing might be fulfilled.
Reason 3 . That God’s omnipotence in this divine mystery, and principal work of God, might be evidently shown. Now, it was not difficult for the power of God that a son should be born of a virgin. For seeing that all secondary causes act by virtue of what they received from God, it is not to be doubted that God can produce all these effects without this or that cause cooperating, which would otherwise exist by them. Yet not only the power of God appeared in that work, but also his wisdom. And it was most agreeable to his wisdom that so singular a substance of human nature should, in as singular a manner be brought to pass, that it differed from all others. For previously all men were made in three manners:
1. Without the concurrence of either man or woman, as in the creation of Adam. 
2. Without the concurrence of woman, as in the production of Eve. 
3. By the concurrence of a man and woman, as in all ordinary generation afterwards. And this only is the proper and unique birth of Christ, by and of a woman, without the concurrence of a man.
1 “Virgin” here may simply mean that Mary had not been with a man till after Jesus’ birth. “Then Joseph, being aroused from sleep, did as the angel of the Lord commanded him and took to him his wife, and did not know her till she had brought forth her firstborn Son. And he called His name JESUS” (Matthew 1:24-25). There is a doctrine of the perpetual virginity of Marywhich was widely supported by the early church fathers, and affirmed in a number of ecumenical councils. Early Protestant reformers like Luther held it as well; even Hugh Latimer and Thomas Cranmer of the English Reformation followed the tradition. Later reformation doctrine, however, rejected it as having no Scriptural basis; and so it was kept out of the Reformation Creeds.
Reason 4. That it might easily appear how the contagion of sin might be removed from the human nature of Christ.
Use. Of Confirmation: for strengthening our Faith about the person of Christ — that he was both the Messiah promised of old, and the promised seed of the woman in the unique manner which that promise seems to have intended; namely, the son of man. That is he was born of a woman who herself descended from Adam and other men in an ordinary way; but she was made the mother of a son not in a vulgar or common way, but miraculously and without the company of a man. So that from Jesus’ first conception, all things were supernatural in him, about which our minds being busied, should always be lifted up to supernatural contemplations, laying aside carnal and worldly thoughts.
Doctrine 4. The Holy Spirit was the principal efficient cause of this generation.
It is from these words in the Text: is of the Holy Spirit. The particle does not denote any material cause, but the efficient cause. So that of the Holy Spiritsignifies as much as if it had been said, by the power of the Holy Spirit, and his operation. Now this is attributed to the Holy Spirit for these reasons:
Reason 1. Because it was a miracle, and all miracles by appropriation are attributed to the Holy Spirit.
Reason 2 . Because the principal work here was of Sanctification — for the lump of human nature which was to be assumed by Christ, was in a singular manner sanctified and cleansed from all spot of sin; and all Sanctification is uniquely attributed to the Holy Spirit.
Reason 3 . Because the Holy Spirit was to rest on and dwell in Christ without measure. It was only reasonable, therefore, that the Holy Spirit should prepare and make such a dwelling for himself, as he also prepares his dwelling in the sons of God by adoption.
Question. It may be questioned whether Christ may be called the Son of the Holy Spirit?
Answer. It cannot be said, 1. Because it would bring some confusion about the personal relations and proprieties in God, and in the Persons [of the Godhead]. 2. Because the Holy Spirit did not produce a new person when he made Christ to be begotten or generated; nor was it a new nature, which he produced after his own nature (or of the same essence with his own nature).
Use 1. Of Direction: in our Faith, and in all our thoughts that we have of Christ, that we grant that all which is in him is spiritual, holy, and full of mystery. Nor should we ever doubt any part of this mystery; because all this, just as it is above the common order of things, so it is above the reach of common nature. Yet we may always receive and conceive this: that none of all these things is above the divine power of the Holy Spirit, nor is there anything irrelevant or unfitting in that thing which is wholly managed by the Holy Spirit.
Use 2 . Of Direction: in our Practice, as to the certainty of our salvation, which depends upon this: if we are sure that we are conformable to Christ in his nativity, life, death, and resurrection. And the beginning of this conformity to Christ is to be taken from this: if we are spiritually regenerated by the Holy Spirit, as Christ was born of Mary through the efficiency and operation of the Holy Spirit. And this is the self-same thing which the Apostle Peteradmonishes us to do, that we study to make our vocation and election sure, 1 Peter 1:10.