As to the position of Christianity, let it be stated without any hesitation or equivocation that its Divine origin is unconditionally acknowledged, that the Sonship and Divinity of Jesus Christ are fearlessly asserted, that the Divine inspiration of the Gospel is fully recognized, that the reality of the mystery of the Immaculacy of the Virgin Mary is confessed, and the primacy of Peter, the Prince of the Apostles, is upheld and defended. The Founder of the Christian Faith is designated by Bahá’u’lláh as the 'Spirit of God', is proclaimed as the One Who 'appeared out of the breath of the Holy Ghost', and is even extolled as the 'Essence of the Spirit'. His mother is described as 'that veiled and immortal, that most beauteous countenance', and the station of her Son eulogized as a 'station which hath been exalted above the imaginings of all that dwell on earth,' whilst Peter is recognized as one whom God has caused 'the mysteries of wisdom and of utterance of flow out of his mouth.

Shoghi Effendi, Lights of Guidance, p. 490

It would be sacrilege for a Bahá’í to believe that the parents of Jesus were illegally married and that the latter was consequently of an illegal union. Such a possibility cannot be even conceived by a believer who recognizes the high station of Mary and the Divine Prophethood of Jesus Christ. It is this same false accusation which the people of His Day attributed to Mary that Bahá’u’lláh indirectly repudiated in the Íqán.

Shoghi Effendi, Lights of Guidance, p. 489

What science calls a virgin birth we do not associate with that of Jesus Christ, which we believe to have been a miracle and a sign of His Prophethood. In this matter we are in entire agreement with the most orthodox church views.

Shoghi Effendi, High Endeavours - Messages to Alaska, p. 70

With regard to your question concerning the Virgin Birth of Jesus; on this point, as on several others, the Bahá’í Teachings are in full agreement with the doctrines of the Catholic Church. In the 'Kitáb-i-Íqán' (Book of Certitude) p. 56, and in a few other Tablets still unpublished, Bahá’u’lláh confirms, however, indirectly, the Catholic conception of the Virgin Birth. Also ‘Abdu’l-Bahá in the 'Some Answered Questions', Chap. XII, p.73, explicitly states that 'Christ found existence through the Spirit of God' which statement necessarily implies, when viewed in the light of the text, that Jesus was not the son of Joseph.

Shoghi Effendi, Lights of Guidance, p. 489