Even sincerity is not the same as authenticity. Sincerity means that a person, when expressing himself, does not deceive, that speaks according to what he feels, what he sees. But this is not enough for the person to be authentic.
Authenticity is an immediate, direct, intelligent, simple response to every situation. It is a response that occurs instantaneously from the depths of being, a response that is complete in itself, and that, therefore, leaves no residue, does not leave energy to be solved, does not leave emotions or aspects to be solved. It is something that, because it is total action, an action in which the person expresses it and gives it all, liquidates the situation in the same moment and generates confidence.
Authenticity is the simplest thing there is, because it is what arises after the complex, the compound, the acquired have been eliminated.
Another aspect of authenticity is that it provides the evidence, the certainty, the clarity, at every moment, to assess every situation, in reality, the situation implies, already in itself, the answer, because the situation and the response are not two different things, but they constitute only one thing. This is only possible to see when the mind is not divided, when the mind is open and perceives, in a single field of vision, everything that is happening at that moment.
Authenticity is being and being in the center, therefore at the optimum point to go in any direction, at the same time, a constant experience of satisfaction, joy, happiness, because that deep content, that content of fullness.