When Jesus was asked why he and his disciples did not practice fasting, he answered with a vivid picture. A wedding is always a time of special festivity.
So Jesus compares himself to the bridegroom and his disciples to the bridegroom's closest friends. How could a company like that be sad and grim? A wedding is not a time for fasting, but for the rejoicing. But Jesus does tell us two things in the gospel.
He tells us that to be his follower is to know the real meaning of joy. There’s simply no room for a gloomy kind of Christianity for a true disciple.
Together with this assurance, however, there is also a reminder about the reality of life. “When the bridegroom is taken away, then they will fast”, Jesus says. He was being realistic. There is sadness and pain in life, and being Christ’s follower does not guarantee that we will never experience disappointment and suffering.
What it does guarantee, however, is that nothing in life, not even pain and suffering can take away the happiness that our faith in Christ brings.