Mary
John 19:26-27
Woman, behold thy son. After that, he saith to the disciple: Behold thy mother. And from that hour, the disciple took her to his own.
Context of the passage
From the Cross, in his final moments, Jesus entrusts his mother Mary to the beloved disciple, traditionally identified as John.
Catholic reading
Since the beloved disciple represents all faithful disciples, Jesus' gift of Mary as 'mother' to John extends spiritually to every Christian, the scriptural basis for honoring Mary as spiritual Mother of the Church.
Common objection
This is simply Jesus making a practical arrangement for his mother's care in his absence, nothing more.
Response
John's Gospel is saturated with symbolism, and given that John rarely names himself, functioning as 'the disciple Jesus loved' representing all believers, this deeply theological Gospel would not present such a poignant scene as merely a domestic footnote.