Because the Lord has created us, He knows us perfectly. He knows how to break through our resistance to His will. He knows how to penetrate our hearts and transform us. He knows how to love us. In His infinite wisdom, He has decided to do especially astounding miracles of conversion, repentance, deliverance, and healing on this day when we celebrate the taking of Mary to heaven. This makes today a holy day, a special day set apart from most other days. This is why the Church usually makes this day a holy day of obligation. The Church obliges us to join in the celebration of the Mass today so that we will not miss out on the amazing graces of this feast day.
Today, people afraid of death will be freed. Death will lose its sting (1 Cor 15:55). People who feel hopeless will become hopeful. They will proclaim the greatness of the Lord (Lk 1:46), for they will believe that they will go to heaven, see Jesus face to face, and rejoice forever in His love. Today, many lukewarm Christians will repent, forgive, and be forgiven. Then they will be on fire with love for God. On this great feast day, the Lord will turn this world around by deposing "the mighty from their thrones" and raising "the lowly to high places" (Lk 1:52).
Today, enter God's throne room. With Mary, all the saints, and the angels, praise and worship the Lord. This is a holy day.