All intellectual giants prove themselves but pygmies before the Absolute Omniscient Omnipotence who reserves the right to give Himself away through His own agents alone. T o our best knowledge and sincerity, however, we should see not to submit to a false agent. Here of course, we can't help ourselves very much, because in our present state we are mainly guided by our previous samskara, or acquired nature. Birds of the same feather flock together. Yet, although we are generally overpowered by habit, there is still the possibility of free choice to a certain extent, especially in the human species, otherwise correction becomes impossible, and punishment mere vengeance.
Reality can assert itself.
Light does not require darkness for its positive proof. The sun by itself can establish its supremacy over all other lights. Both functions of the Absolute help an individual soul, a disciple, to reach the absolute goal. In our fallen state we cannot catch the proper direction of the inner guide, so the merciful manifestation of the preceptor without is our sole help and hope. But at the same time, it is only by the grace of the guru within that we can recognize the real preceptor without, and submit to his holy feet.