Matthew 1:20

‘But when he thought on these things, behold, an angel of the Lord appeared to him in a dream, saying, “Joseph, you son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit.” '

Joseph dropped off to sleep thinking over how he would go about the arrangements, and probably deeply grieved over it. How natural this sounds. And then while he was asleep he had a dream. Such dreams were not common in the New Testament. Note that none of Luke's accounts indicate such a dream situation, for Luke almost ignores Joseph at this stage, while here in Matthew there was no prophecy by Joseph and thus a dream was sufficient. This was taking place away from the centre of things in the house of Joseph. There is nothing of the excitement of Luke, only grief. It is a private situation between him and the Lord. And there is no imitation of Luke (or vice-versa).

And in the dream he is addressed by ‘an angel of the Lord'. This situation is unique. The angel of the Lord appears in the service of God regularly in the Old and New Testaments, but never, apart from to Joseph, in a dream (see Matthew 1:20; Matthew 1:24; Matthew 2:13; Matthew 2:19). Usually the angel only appears where there is a face-to-face confrontation. Furthermore in the Old Testament the ‘angel of the Lord' is usually, but not always, synonymous with God. Thus this situation is unique. This is further demonstration that Matthew is describing it as it was, not inventing it on the basis of Old Testament ideas. Furthermore of the evangelists only Matthew ever speaks of ‘the angel of the Lord', a further sign of his own Jewishness, and the fact that he has Jews very much in mind. Note also that there is no physical ‘appearance' of an angel described. It is all in Joseph's dream.

Some may not be happy with information received in a dream. But history (even recent history) contains many examples of accurate information received through dreams and premonitions, too many to be totally discounted, for it is a way by which God sometimes chooses to speak (Genesis 23:6; Genesis 28:12; Genesis 31:24; 1 Kings 3:5). Drugs can also speak through dreams too, but not reliably. However this was no drug induced dream. The Israelites in fact seem to have expected that information would sometimes come through dreams (Numbers 12:6; Deuteronomy 13:1; 1 Samuel 28:6). But it was very much a secondary method of revelation (Numbers 12:6).

On the other hand Scripture has also warned against over-reliance on dreams, and against the danger of ‘dreamers of dreams' (Deuteronomy 13:1). Thus in the New Testament, in spite of God's words through Joel (Acts 2:18) mentioned at Pentecost, dreams are a rarity. Both Jewish and Gentile believers receive information from God through visions rather than dreams (Acts 9:10; Acts 10:3; Acts 16:9; Acts 18:9). A vision of the night was not necessarily a dream. Paul may well have been consciously engaged in prayer. It must be seen as more than a coincidence then that Joseph alone is seen as receiving all his messages, usually from the angel of the Lord, in dreams, and that over a period (see also Matthew 2:13; Matthew 2:19; Matthew 2:22). This suggests that Joseph was in fact unusually susceptible to dreams, and had the gift mentioned in Acts 2:18, which would explain their unusual prominence in this account. That the Magi (Matthew 2:12) and Pilate's wife (Matthew 27:19) also received their messages through dreams is explicable by the fact that they were not strictly ‘believers', even though the Magi may have been well on the way to being so. Unbelievers did not receive direct visions, unless with the purpose of making them believers. Warnings to unbelievers thus necessarily came through dreams, as they had to people like Laban of old (Genesis 31:29).

In his dream the angel of the Lord tells Joseph not to be afraid of finalising his marriage to Mary his (betrothed) wife, because what is conceived in her is ‘born of the Holy Spirit', ‘ek Pneumatos Hagiou' (see on Matthew 1:18). What is happening is the work of God and Him alone. ‘The Holy Spirit' (or ‘Spirit of God') is a term which is always used to describe God in invisible action where the results are outwardly apparent, and in the Old Testament it is very closely associated with the idea of God Himself. The Holy Spirit is never thought of as having a form. He is pure Spirit. (There is only one remarkable exception to this in the whole of Scripture, and that a unique one for a unique purpose, as found in Matthew 3:16).

‘Do not be afraid.' Normally to take someone as a wife who was bearing someone else's child would be seen as degrading and disobedient to the Law. It would be the equivalent of adultery. Under normal circumstances Joseph would not even have considered it. It went against everything in which he believed. Thus it is clear that Joseph certainly came to believe in the virginal conception of Jesus, and he would have taken some convincing! Those who do not accept the virgin birth have to explain how Joseph, the Son of the Davidic house, was persuaded to go against all his breeding at a time when such things were seen as all important (he could hardly have been in doubt about whether the child was his or not). However, by saying nothing at the time he at least kept their shame in the eyes of others down to the thought that they had had sexual relations when only betrothed, something not really satisfactory in the most righteous circles, but certainly understandable and something which in some ways would be sympathised with. The Mishnah sees sexual relations as sometimes bringing about a betrothal, and never specifically frowns on the idea.

The Holy Spirit is sometimes connected with the birth process in the Old Testament (see Job 33:4; Psalms 104:30), but here it is different. He takes it over completely in His creative power. Mary is merely a passive instrument. This is unquestionably totally different from anything that has happened before.

(It is completely different from the so-called virgin births of Greek mythology where they were not really virgin births at all but the result of gods having sexual relations with the woman in question).