Since Jesus was born of "the substance" of the Virgin Mary, how was He without original sin?

Since Jesus received His human nature or “substance” from His mother, who was a sinner, how could Christ have been born without original sin? From one of our Ask R.C. events, R.C. Sproul considers the mystery of the incarnation. Message us for clear, concise, and trustworthy answers to your biblical and theological questions at https://ask.ligonier.org/