With his claimed death of the Christian God, Nietzsche saw that as signalling a new possibility for what he called 'the higher man' to become Lord and Master, no longer beholden to divine authority.
Heidegger formulated this insight in his philosophical poem The Thinker as Poet (Aus der Erfahrung des Denkens) as follows
"We are too late for the gods and too early for Being.
Being's poem, just begun, is man."In other words, God being dead, there is no longer any authority higher than personal conscience, and the higher the conscience, itself governed by level of consciousness, the higher the individual who exercises it.
It was indeed in his polemic On the Genealogy of Morality, Second Essay, that Nietzsche foresaw the sovereign individual, fruit of millennia of history, as calling his free will and dominant instinct his conscience.
Small men become, in Nietzsche's opinion, but pale imitations of great men offering the necessary resistance for these great men to reach their highest heights in terms of enlightenment and creativity.
And in his estimation the errors of great men are more admirable than the truths of little men for being historically more fruitful.