‘Dvitiyad vai bhayam bhavati: Certainly fear is born of duality.’ Whenever and wherever there is a sense of two, fear or suffering can exist.
“There is a Light that shines beyond. Shines beyond all things on earth. Beyond us all, beyond the heavens, beyond the highest heaven. This is the light that shines in our heart. The little space within the heart is as great as this vast universe. The earth and heavens are there. And the sun and moon and the stars. Fire and lightning and the winds are there. And all that now is. And all that is not. For the universe is in Him, and He dwells within our heart. Even here, in this life, the universe is conquered by those whose mind is established in equanimity. Flawless indeed and equally present everywhere is Brahman. Therefore they are established in Brahman. He whose Self is untouched by the external knows that happiness which is in the Self. His Self joined in union with Brahman, enjoys eternal happiness. Even here, in this life, the universe is conquered by those whose mind is established in Brahman.” – Chandogya Upanishad
“You are woman. You are man. You are the youth and the maiden too. You are the old man hobbling along with a staff. Once born, you are the face turned in every direction. You are the dark blue butterfly, you are the green parrot with red eyes. You are the thundercloud, pregnant with lightning. You are the seasons, you are the seas. You are without beginning, present everywhere. You, from whom all worlds are born.” (Shvetaashvatara Upanishad 4.3-4)