Despondency is not religion, whatever else it may be. By being pleasant always and smiling, it takes you nearer to God, nearer than any prayer.
How can those minds that are gloomy and dull love? If they talk of love, it is false; they want to hurt others. Think of the fanatics; they make the longest faces, and all their religion is to fight against others in word and act. Think of what they have done in the past, and of what they would do now if they were given a free hand. They would deluge the whole world in blood tomorrow if it would bring them power. By worshipping power and making long faces, they lose every bit of love from their hearts. So the man who always feels miserable will never come to God.
It is not religion, it is diabolism to say, ‘I am so miserable.’ Every man has his own burden to bear.
If you are miserable, try to be happy, try to conquer it. God is not to be reached by the weak. Never be weak. You must be strong; you have infinite strength within you. How else will you conquer anything? How else will you come to God?
At the same time you must avoid excessive merriment, Uddharsha, as it is called. A mind in that state never becomes calm; it becomes fickle. Excessive merriment will always be followed by sorrow. Tears and laughter are near kin. People so often run from one extreme to the other. Let the mind be cheerful, but calm. Never let it run into excesses, because every excess will be followed by a reaction.
Source - The Complete Works of Swami Vivekananda, 4.11