Roman Catechism 5.26

Chapter 5 — Part I: The Creed — Article III: Who Was Conceived by the Holy Ghost, Born of the Virgin Mary

Section 26. Duty Of Spiritual Nativity — We must also take care lest to our great injury it should happen that just as there was no room for Him in the inn at Bethlehem, in which to be born, so likewise now, after He has been born in the flesh, He should find no room in our hearts in which to be born spiritually. For since He is most desirous of our salvation, this spiritual birth is the object of His most earnest solicitude.