Mary - "Blessed is she who believed"
The Virgin Mary most perfectly embodies the obedience of faith. By faith Mary welcomes the tidings and promise brought by the angel Gabriel, believing that "with God nothing will be impossible" and so giving her assent: "Behold I am the handmaid of the Lord; let it be [done] to me according to your word." Elizabeth greeted her: "Blessed is she who believed that there would be a fulfilment of what was spoken to her from the Lord." It is for this faith that all generations have called Mary blessed.
Source: Catechism of the Catholic Church (Vatican.va)