The Conquest of Fear

When indeed this (soul) makes in the One even the smallest break, then there is fear. (Taittiriya Upanishad, 2:7:1)

The triad of the seer, seeing and the seen, exists in the soul. Atman (the Self) is above this illusion of duality, which does not, in fact, exist. To cut out fear is the object of this upanishadic statement. Not to have the fear of death one must either be above or below humankind. Human beings are always afraid, even if our soul longs for eternal security. While the ego is extrovert it sometimes experiences joy, but that joy is always mixed with fear.

At-onement with the Reality underlying all phenomena is the one method of overcoming fear, but as long as one sees one little break in at-onement with the Absolute, then fear remains.
Dreamless sleep is a daily state in which no fear exists and which induces fearlessness, since there is no duality experienced in this state of consciousness; nevertheless, it is imperfect, because it lacks illumination and is transitory.

The wave, while still a wave, is subject to the fear that it will break. When the wave realises that it is water, it is utterly fearless, because no sense of duality is left in the wave.