Sinless Mary

[LoganBice]

It may be helpful to research about the Ark of the Covenant, and the holiness it contained.

Once you do that, then showing it to be the prefigurement of Mary, as the Ark of the New Covenant, should help to bridge their understanding.

I heard a good thing about that from someone. He said “the ark of the old convenient was made of incorruptible wood, why would Mary not be incorruptible”