Yeshua of Nazareth said:
Those who know the All
yet do not know themselves
are deprived of everything.
(CF. Matt 16:26; Mark 8:36; Luke 9:25.)
What is meant by this self-knowledge that is so fundamental to the Gospel of Thomas? Here is commentary about this. . . and it very thought provoking (and has some striking parallels with Buddhism):
What is the value of the greatest knowledge if it knows not the agency of knowing? Vast knowledge without inner transformation is an illusion. It is mere show.
Self-knowledge, so fundamental to the Gospel of Thomas, has nothing to do with self-analysis or narcissistic introspection. It is a process of keenly observing our reactions and emotions without judging or explaining them. In this attentive regard, neutral and compassionate, we discover what is and who we are.