Spirit of man sexually begotten by Heavenly Father

Latter-day Prophets Speak: Selections from the Sermons and Writings of Church Presidents, Book 5; “There is not a person here today but what is a son or a daughter of that Being. In the spirit world their spirits were first begotten and brought forth, and they lived there with their parents for ages before they came here. This, perhaps, is hard for many to believe, but it is the greatest nonsense in the world not to believe it. If you do not believe it, cease to call Him Father; and when you pray, pray to some other character. -Brigham Young, Journal of Discourses 4:216, February 8, 1857”

If God is a spirit as His word tells us in John 4:24 how could He have sex to beget us spiritually before we came here to earth?