Trust is the isomorphic of self-valuing being, that which aligns being to being "magically" by way of ordered relations dependent on and reducible in part to each related being in question, since any such being has the power to remove its trust from the wider system of relations of trusting. When we trust one another we give a degree of power and we take a degree of power; the power given is proportionate to the possibility for an equal or even greater degree of power taken (removal of trust). Trust therefore requires difference and separation of ontic and epistemic conditions of beings, physical distance in space and time as well as mental and emotional distances of meaning and significance. Trust is not necessary where distances of these types are absent; if trust is not necessary then trust becomes superfluous and would exist only as a secondary representation of the non-differentiated relations themselves bringing together beings 'absolutely', which is to say cutting off the inner life in order to establish a common outer life. Trust isn't contrary to this commonness of the outer (non-individual) life, it simply has no meaning within it. It is impossible to conceive of what "trust" could mean to non-differentiation, except for total and complete alignment to the conditions of undifferentiated relatedness.
Trust itself is never absolute, and even in cases where it seems absolute (for instance, in love) trust is reducible to the differentiations that mark separate beings and keep their respective inner worlds and lives private and to some large degree unknowable; trust posits this inner world as metaphor for relating as such, which gives being. We are capable of trust, and we are incapable of trusting completely---these two expressions are synonymous.
We also trust ourselves, being to itself, because we do not entirely know ourselves and therefore have much in us into which to move newly and originarily, and therefore always have a novelty of possible exposure and insight capable of renewing being and preventing stagnation and total limitation of an "end". Trust is openness to oneself as well as openness to others, and this isn't simply a psychological or teleological or moral position but in fact an entirely onto-epistemological one, since this is how being is constructed necessarily. Like a good scientific theory, trust must be both in principle and in practice falsifiable. Truth and trust have a similar etymology.
The limit of being is the limit of trust, of being's ability to trust other beings, which is also connected to its ability to trust itself. Trusting posits the other in terms of oneself, of one's own self-valuing that proves confident, strong, sure and truth-grounded enough to be capable of trust, since to be capable of trust also means to be capable of having that trust violated or betrayed. Trust gives a piece of our being to another, and we receive a piece of their being in kind; trust is entirely "metaphysical; this ensures that worlds appear and are being-centric, which ultimately means truth-centric and fundamentally open-ended. This therefore orients the being-in-truth of trusting being to the phenomenological climb of the universal, impregnation being with existentia.