[26] When Jesus therefore had seen his mother and the disciple standing whom he loved, he saith to his mother: Woman, behold thy son. [27] After that, he saith to the disciple: Behold thy mother. And from that hour, the disciple took her to his own. John, Chapter 19
All of it [Roman Catholicism] as seen through the centuries -- in not what Christ "taught", or else the earliest generations of Christians were laggardly, with only those coming along centuries later doing "as Christ taught", particularly in regards to "Mary".