In today's Gospel reading from Matthew 9, Jesus explained why his disciples did not fast: "Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from therm, and then they will fast." We are happy because the Lord is always with us. At the same time, we are sorry because the world continues to sin against him. So we experience both joy and sorrow at the same time. By offering up our sorrows to the Lord, the joy outweighs the sorrow always.