Swami Vivekananda says (Complete Works of Swami Vivekananda V3 p 94-95 or http://cwsv.belurmath.org/volume_3/vol_3_frame.htm):
We may well say that we are all playing in this universe. Just as children play their games, just as the most glorious kings and emperors play their own games, so is the Beloved Lord Himself in sport with this universe. He is perfect; He does not want anything. Why should He create? Activity is always with us for the fulfilment of a certain want, and want always presupposes imperfection. God is perfect; He has no wants. Why should He go on with this work of an ever-active creation? What purpose has He in view? The stories about God creating this world for some end or other that we imagine are good as stories, but not otherwise. It is all really in sport; the universe is His play going on. The whole universe must after all be a big piece of pleasing fun to Him. If you are poor, enjoy that as fun; if you are rich, enjoy the fun of being rich; if dangers come, it is also good fun; if happiness comes, there is more good fun. The world is just a playground, and we are here having good fun, having a game; and God is with us playing all the while, and we are with Him playing. God is our eternal playmate. How beautifully He is playing! The play is finished when the cycle: comes to an end. There is rest for a shorter or longer time; again all come out and play. It is only when you forget that it is all play and that you are also helping in the play, it is only then that misery and sorrows come. Then the heart becomes heavy, then the world weighs upon you with tremendous power. But as soon as you give up the serious idea of reality as the characteristic of the changing incidents of the three minutes of life and know it to be but a stage on which we are playing, helping Him to play, at once misery ceases for you. He plays in every atom; He is playing when He is building up earths, and suns, and moons; He is playing with the human heart, with animals, with plants. We are His chessmen; He puts the chessmen on the board and shakes them up. He arranges us first in one way and then in another, and we are consciously or unconsciously helping in His play. And, oh, bliss! we are His playmates!
You learn to see evil or bad. Small babies see no evil. The Astavakra Samhita (I.7) says:
Virtue and vice, pleasure and pain, are of the mind, not of you, O all-pervading one. You are neither doer nor enjoyer. Verily you are ever free.
and in I.11:
He who considers himself free is free indeed, and he who considers himself bound remains bound. 'As one thinks, so one becomes' is a popular saying in this world, and is quite true.
Light shines on everything, so the Lord is in everything. See the Lord shining in everything.
Krishna says in the Gita (II. 14)
Notions of heat and cold, of pain and pleasure, arise, O son of Kunti, only from contact of the senses with their objects. They come and go; they are impermanent. Endure them, O Bharata.
And in II. 19:
He who looks on the Self as the slayer, and he who looks on the Self as the slain--neither of these apprehends aright. The Self slays not nor is slain.
All notions of bad and good are only in your mind. Remove the thorn of tamas with the thorn of sattva. Then throw both away. Your mind cannot see two things at the same time. You can only see one thing at a time. If you are seeing evil, then you are not seeing God. If you see God, you cannot see evil. You cannot change the world, but you can change your mind. See God in everything. The world will become transformed.
Vivekananda says in V5 p 254 or http://cwsv.belurmath.org/volume_5/vol_5_frame.htm :
No breathing, no physical training of Yoga, nothing is of any use until you reach to the idea, "I am the Witness." Say, when the tyrant hand is on your neck, "I am the Witness! I am the Witness!" Say, "I am the Spirit! Nothing external can touch me." When evil thoughts arise, repeat that, give that sledge-hammer blow on their heads, "I am the Spirit! I am the Witness, the Ever-Blessed! I have no reason to do, no reason to suffer, I have finished with everything, I am the Witness. I am in my picture gallery — this universe is my museum, I am looking at these successive paintings. They are all beautiful. Whether good or evil. I see the marvellous skill, but it is all one. Infinite flames of the Great Painter!"