"If one drop of corruption makes the purest water worthless, as the slightest savour of bitterness spoils the most delicate viands, how can it be that the word of truth and holiness can proceed profitably from impure lips and an earthly heart? No; as is the tree, so is the fruit; 'beware of false prophets,' says our Lord; and then He adds, 'from their fruits ye shall know them. Do men gather grapes of thorns, or figs of thistles?' Is it not so, my brethren? which of you would go to ask counsel of another, however learned, however gifted, however aged, if you thought him unholy? nay, though you feel and are sure, as far as absolution goes, that a bad priest could give it as really as a holy priest, yet for advice, for comfort, for instruction, you would not go to one whom you did not respect. 'Out of the abundance of the heart, mouth speaketh;' 'a good man out of the good treasure of his heart bringeth forth good, and an evil man out of the evil treasure bringeth forth evil'.
So then is it in the case of the soul; but, as regards the Blessed Mary, a further thought suggests itself. She has no chance place in the Divine Dispensation; the Word of God did not merely come to her and go from her; He did not pass through her, as He visits us in Holy Communion. It was no heavenly body which the Eternal Son assumed, fashioned by the angels, and brought down to this lower world: no; He imbibed, He absorbed into His Divine Person, her blood and the substance of her flesh; by becoming man of her, He received her lineaments and features, as the appropriate character in which He was to manifest Himself to mankind. The child is like the parent, and we may well suppose that by His likeness to her was manifested her relationship to Him. Her sanctity comes, not only of her being His mother, but also of His being her son. 'If the first fruit be holy,' says St. Paul, 'the mass also is holy; if the mass be holy, so are the branches.' And hence the titles which we are accustomed to give her. He is the Wisdom of God, she therefore is the Seat of Wisdom; His Presence is Heaven, she therefore is the Gate of Heaven; He is infinite Mercy, she then is the Mother of Mercy. She is the Mother of 'fair love and fear, and knowledge and holy hope'; is it wonderful then that she has left behind her in the Church below 'an odour like cinnamon and balm, and sweetness like to choice myrrh'?" - Venerable John Henry Newman, C.O. , "On the Fitness of the Glories of Mary", Discourses to Mixed Congregations