Self realization alone makes one fearless – Teachings Upanishads

Whatever is performed with knowledge, shraddha and meditation becomes more effective. (Chandogya Upanishad, 1.1.10.)

Fear arises from duality. (Brihadaranyaka Upanishad 1.4.2)

Self realization alone makes one fearless. (Brihadaranyaka Upanishad 1.4.2)

Of the cows of different colours the milk is of just one colour. The wise man regards the Atman like the milk and the different manifestations like the cows. (Brahmabindu Upanishad, 19)

This Atman cannot be attained by the study of scriptures or by intelligence or by much hearing of sacred books. It is attained by Him who earnestly seeks It. To him the Atman reveals Its true form. (Katha Upanishad, 1.2.23)