With no description of Mary's assumption in Christian scripture, there's no way of knowing how, where, or when she died — but those details are secondary to what this day actually celebrates. The idea that Mary, a regular woman of immense faith, was assumed into Heaven, gives Christians hope that, if they hold fast to their beliefs, the same thing will happen to them.
Sometimes called the "first believer," Mary has come to represent the exemplary Christian. Scripture and sermons paint her as the embodiment of God's mercy, forgiving and protecting sinners regardless of their indiscretions. Even the mysterious circumstances of her death can't obscure the piety and service to God she showed in life, which is what's believed to have prompted her assumption.
Although her assumption had been cause for celebration among Catholics and Eastern Orthodox Christians, alike, for centuries, it was finally declared dogma (true and official Christian belief) in 1950. Today, people will observe the Assumption of Mary by attending mass and, in some countries, taking the day off from work and school to reflect on the power of her faith.
In his remarks to the worshippers gathered in St. Peter Square today, Pope Francis said Mary's assumption is a reminder that salvation waits for every Christian, especially the poor and oppressed. He praised her strength of faith and called on her continued protection of observant Christians: "We ask her to keep us and support us; so that we may have a strong, joyous and merciful faith... May she help us to be holy, so that we might meet with her, one day, in Heaven.”