Someone writes: Mary had children. Christ had half-brothers and sisters. The Bible tells us so. Therefore, while no one is disputing the fact of Mary's virginity until after she gave birth to Jesus, the Bible invalidates the Catholic man-made tradition that Mary remained a perpetual virgin. You know the Bible also calls cousins, cousins: And behold, your COUSIN Elisabeth hath also conceived a son in her old age (Luke 1:36). Luke doesn't call Elisabeth her SISTER, but her cousin.
My response: According to the bible and tradition Mary gave birth to only Jesus Christ. There is no other recording of her giving birth to anyone. The term "brothers" does not translate into literal siblings in scripture, but to ANY relative (uncle, nephew, cousins, etc.). How do we know this? Because the bible shows us. Let's go to the scriptures to see who is called "brother" and what their real relationship is then I will respond to the "cousins" Mary and Elizabeth. In Gen. 14 we see Lot call Abraham "brother" when the fact is Lot was Abraham's nephew. They were not siblings, but uncle and nephew. Another example from scriptures would be Jacob and his Uncle Laban. Scripture calls them "brother" when in fact they are not siblings at all. The same is done with Jesus and his "brothers" in scripture. They are family relatives (uncles, cousins, etc.), but they are not literal siblings because Mary didn't give birth to anyone but the Christ, God Incarnate. Now, getting back to Mary and Elizabeth being "cousins". It is by tradition that they are referred to as 'cousins' not the original written text as it says "relative" or "kinswoman". I hope that helps dispel your views that "the Bible invalidates the Catholic man-made tradition". The Catholic Church is teaching the faith the same today as it has since Christ created the Church.