|Fortunately most people today realize that
it takes a male and female to conceive a child; and the case wasn't any
different with Mary and Joseph. However, there are still a few out there
that believe that women get pregnant without having sex. Can you imagine
Mary explaining to her husband that the child wasn't his, when he was the
only man to bed her?
All that, to say this; the immaculate conception hoax was the church's concoction; it was to absolve Mary of all sin. Let us remember here, that women being particularly independent and innately intelligent, happen to appreciate knowledge; are we saying the whole of humanity's sin is based on Eve eating a piece of fruit? Fortunately, most of us today aren't that gullible. Intelligent people are insulted by such a stupid accusation.
So, the whole argument set forth within the organisation for men that couldn't get laid, was to create a story absolving her of all human traits at the moment of her conception, so that she could qualify to give birth to their new god and be exempt of heresy.
Now this didn't happen for a long time mind. The church men argued back and forth, as they didn't want the common folk to worship her more than their "man" god; but the simple minded folk did anyway. So by the 12th century, the church knew it had a problem, here they were trying to convince the congregation that it was supposed to be Jesus and god as the stars of the show, but of course people aren't that daft, they knew it was a woman that gave birth and she should get the credit.
Can you believe the church heatedly argued about this for 700 years? They thoroughly opposed the proposed doctrine, as it would partially negate the total oppression of women if they exalted Mary.
Finally, after much debate, these women haters adopted an article of the faith by Pope Pius 1X in 1854. Henceforth, every christian was commanded to believe that Mary "at the instant of her conception, was preserved immaculate from all stain of original sin, by the singular grace and privilege granted to her by their god".
But the churchmen still faced a perplexing dilemma; and that was they still couldn't explain to the people about Mary's father, as he wasn't a god or a spirit, but a living breathing regular man, and since he had sexual intercourse with Mary's mother, it would mean using the medium of transmission of original sin (of snacking on fruit) by the church's own teaching!
The church was so embarrassed, it had to go to plan B...Have faith.