The Mishnah tells us, "There were no days as joyous for the Jewish people as the 15^th of Av and Yom Kippur." 

     I understand why the 15th of Av was such a happy day with couples finding each other and other such wonderful things happening, but why should Yom Kippur be happy? It is a day of fasting and recalling our sins!

     Because it is the day when our sins are forgiven, a day when we can return to our loving Father in peace.