Gaudete Sunday is the third Sunday of Advent in the Catholic Church. It comes from the Latin word Gaudete ("Rejoice"), the first word of the introit of this day's Mass.
Gaudete in Domino semper: "Rejoice in the Lord always. I shall say it again: rejoice! Your kindness should be known to all. The Lord is near. Have no anxiety at all, but in everything, by prayer and petition, with thanksgiving, make your requests known to God. Then the peace of God that surpasses all understanding will guard your hearts and minds in Christ Jesus. (Phil 4:4-7)
In some churches, the altar is decorated with rose colored cloths and the priest wears rose vestments on this day, a sign of great joy during the penitential season of Advent. Why joy? Because the Lord is near. And this year, because we only have a three-week advent in effect (because Christmas Eve is next Sunday night), Advent will be particularly short, so the Lord is indeed near.
Please make sure to do the spiritual things you need to do to prepare your hearts and families for Christmas. The Scripture above promises peace and joy in Jesus. I want you to have those gifts as we celebrate this great Solemnity of the Church.