Most Important Point in Marian Apologetics.
In my opinion the most important point in defending Mary is to examine the question of motivation.
Most Protestants that wish to engage in a conversation on the brothers of Jesus already have firm convictions on what they believe. Often their supposed proof that Mary had other children is their “proof” that Catholicism is wrong. Therefore, their reason for rejecting the Church and her teachings is “justified.”
They are not looking for a Catholic to educate them. Once they find that the Catholic is able to give a good defense for his position they will usually terminate the discussion.
They will stop the discussion not because they are convinced the Catholic position is true. Rather, they think their time will be better well spent with another Catholic who doesn’t know the Bible so well.
So, the opportunity to teach him is lost. And goes on spreading his errors to other Catholics.
For the Protestant thinks that even if he is wrong it is no big deal for them personally. At worst, it would only mean they lost a “tool” to get approval for leaving the Church, or to get Catholics to leave the Church.
Therefore, they have no real motivation to really seek out the truth of the matter on Mary’s Perpetual Virginity. Other than the usefulness of the tool, to them, it is no more important than the question of how many children Mary of Clopas had.
In order to help the Protestant to stay engaged in the conversation until he hears all of the good Catholic arguments we wish to present we need to help motivate him.
For this reason I believe we should very early on in the discussion tell him that he offends God by denying Mary’s perpetual virginity. We owe God gratitude for all of the good works he has done. One of those works is His blessing of grace and work He did in Mary.
With His help, Mary made a consecration to Him and by giving herself to Him she consecrating her whole life as a virgin to and for Him.