Immaculate conception:
“I esteem immensely the Mother of God, the ever chaste, immaculate Virgin Mary.” Zwingli
Perpetual Virgin:
Martin Luther
It is an article of faith that Mary is Mother of the Lord and still a virgin. … Christ, we believe, came forth from a womb left perfectly intact. (Weimer’s The Works of Luther, English translation by Pelikan, Concordia, St. Louis, v. 11, pp. 319-320; v. 6. p. 510.)
Note: an article of faith is required for salvation.
John Calvin
(On the Heretic Helvidius) Helvidius displayed excessive ignorance in concluding that Mary must have had many sons, because Christ’s “brothers” are sometimes mentioned. (Harmony of Matthew, Mark and Luke, sec. 39 [Geneva, 1562], vol. 2 / From Calvin’s Commentaries, translated by William Pringle, Grand Rapids, Michigan: Eerdmans, 1949, p.215; on Matthew 13:55)
[On Matt 1:25:] The inference he [Helvidius] drew from it was, that Mary remained a virgin no longer than till her first birth, and that afterwards she had other children by her husband . . . No just and well-grounded inference can be drawn from these words . . . as to what took place after the birth of Christ. He is called “first-born”; but it is for the sole purpose of informing us that he was born of a virgin . . . What took place afterwards the historian does not inform us . . . No man will obstinately keep up the argument, except from an extreme fondness for disputation. (Pringle, ibid., vol. I, p. 107)
Under the word “brethren” the Hebrews include all cousins and other relations, whatever may be the degree of affinity. (Pringle, ibid., vol. I, p. 283 / Commentary on John, [7:3])
John Wesley
‘I believe that He [Jesus] was made man, joining the human nature with the divine in one person; being conceived by the singular operation of the Holy Ghost, and born of the blessed Virgin Mary, who, as well after as before she brought Him forth, continued a pure and unspotted virgin’ (‘Letter to a Roman Catholic’, The Works of Rev. John Wesley, vol 10, p. 81).