March 25 is the Feast of the Annunciation to the Theotokos (Luke 1:24-38) celebrates the incarnation and the beginning of salvation for all humanity. In this event, all the walls which separated humanity from God are broken down as God unites Himself to His human creatures in order to make us more fully human.
St. Irenaeus (d. 202AD) gives us an idea of how early in Christian history Mary’s role in salvation was understood and appreciated.
“Eve was seduced by the word of the [fallen] angel and transgressed God’s word, so that she fled from him. In the same way, [Mary] was evangelized by the word of an angel and obeyed God’s word, so that she carried him [within her]. And while the former was seduced into disobeying God, the latter was persuaded to obey God, so that the Virgin Mary became the advocate (advocata0 of the virgin Eve. And just as the human race was bound to death because of a virgin, so it was set free from death by a Virgin, since the disobedience of one virgin was counterbalanced by a Virgin’s obedience. If, then, the first-made man’s sin was mended by the right conduct of the firstborn Son [of God], and if the serpent’s cunning was bested by the simplicity of the dove [Mary], and if the chains that held us bound to death have been broken, then the heretics are fools; they are ignorant of God’s economy, and they are unaware of his economy for [the salvation of] man.” (St. Irenaeus in Mary and the Fathers of the Church by Luigi Gambero, pg. 54)