You intended no insult? Then I'm not insulted. But I will still call it sad and disappointing.
I dispute your assertion that the idea of Mary's immaculate sinlessness is of pagan origin. As far as I know, no pagan belief system acknowledges the reality of "Original Sin": the blighting of the human race as a result of a catastrophic act of disobedience on the part of our primordial ancestors at the dawn of human existence.
If there's no Original Sin, then there's nothing problematic about human nature. In that case, there's no need for a Savior, and no question of whether His mother was "full of grace", since, without Original Sin, we're all "full of grace."
(Quickly disprovable by reading Page One of any newspaper on earth.)
Moreover, God's favor of filling people with grace prenatally as a preparation for some special role is a well-established Scriptural pattern. Isaiah, Jeremiah, John the Baptist and others were--- in a partial but analogous way ---- called and enlightened in their mothers' wombs.
It makes sense to think that a person of much greater dignity, with a much more intimate relationship to the Savior, would need a similar but greater gift. This is especially so because she was specifically prepared to give the Messiah his human nature, which in this case must necessarily be sinless and perfect as He takes on flesh from her.
This is the fulfillment of the protoevangelium of Genesis 3:15 -- the enmity between the Serpent and the "Seed of the Woman".
I don't expect this explanation will result in totally and swiftly convincing you on this issue. (!) You can call it mistaken --- with some show of evidence, hopefully --- but don't just flick it away as "man-made" and "pagan." That just suggests a reluctance to engage with the more challenging words and themes of Scripture. And a reluctance to engage doesn't lead to a good and God-honoring discussion.
In that essay he posits the one verse that Catholics use for Mary’s sinlessness. If, somehow, charis or any of it’s derivatives meant to be sinless Stephen and many others would also have been sinless. The use of the word kecharitōmenē first of all never means “sinless” and comes from the word “charis” which only indicates that grace was given to Mary. Again, no definition of those words denote sinlessness. The lengthy attempt at trying to get to sinlessness by Catholic apologists is simply wrong. Never do they prove that the terms mean sinlessness.
That concept of sinlessness of “the queen of heaven” and the “mother of god” is most definitely of pagan origin. Most of the symbolism, vestments, rituals, and holy days the RCC has incorporated into it’s religious practices goes back to Babylonian paganism and has never been instituted by God. In fact, God said not to worship Him with anything taken from pagan practice.
Deuteronomy 12:30 Take heed to thyself that thou be not snared by following them, after that they be destroyed from before thee; and that thou enquire not after their gods, saying, How did these nations serve their gods? even so will I do likewise. 31 Thou shalt not do so unto the LORD thy God:
You think the RCC doesn’t admit that it has taken pagan rituals, symbols, etc?
“We need not shrink from admitting that candles, like incense and lustral water, were commonly employed in pagan worship and the rites paid to the dead. But the Church from a very early period took them into her service, just as she adopted many other things indifferent in themselves, which seemed proper to enhance the splendor of religious ceremonial. We must not forget that most of these adjuncts to worship, like music, lights, perfumes, ablutions, floral decorations, canopies, fans, screens, bells, vestments etc. were not identified with any idolatrous cult in particular; but they were common to almost all cults” (Catholic Encyclopedia, III, 246.)
“When we give or receive Christmas gifts; or hang green wreaths in our homes and churches, how many of us know that we are probably observing pagan customs...the god, Woden, in Norse Mythology, descends upon the earth yearly between December 25th and January 6th to bless mankind...But pagan though they be, they are beautiful customs. They help inspire us with the spirit of 'good will to men', even as the sublime service of our Church reminds us of the ‘peace on earth’ which the babe of Bethlehem came to bestow” (Externals of the Catholic Church, 140).
Catholics can’t deny that the RCC has incorporated pagan practices into its practices. The RCC itself admits that it does. The RCC refuses to hear the words of the Lord as did the Israelites.
“As for the word that thou hast spoken unto us in the name of the LORD, we will not hearken unto thee. But we will certainly do whatsoever thing goeth forth out of our own mouth, to burn incense unto the queen of heaven, and to pour out drink offerings unto her, as we have done, we, and our fathers, our kings, and our princes, in the cities of Judah, and in the streets of Jerusalem: for then had we plenty of victuals, and were well, and saw no evil.” (Jer.44:16-17)