The path laid out in Buddhism is transcendent; not worldly. Logically, it leads to a transcendent state or Dharma (P., lokuttardhamma) this being nirvana which is also ultimate reality. This, I need to emphasize, is a first-person science.
What I mean by the term first-person science is that ultimate reality can only be directly experienced in one's self. There are, however, not a few beginners (not in terms of time but in terms of depth) who believe an enlightened person has visible and discernible marks. Enlightenment is something third-person (what is outside one's self), in other words. I know this is an exaggeration, but it is like believing that an enlightened person has a crown on their head or shoots out golden rays. But this is foolishness. Such people will never awaken with this kind of attitude.
Such people (let me be blunt, they are foolish people) also believe a well qualified teacher can purify them of their defilements or the five obstructions, for example, 1) Drowsiness; 2) Doubt; 3) Ill-will; 4) Restlessness; and 5) Sensual Desire. They also believe that they can come to realize nirvana with the help of their teacher's own penetration and power.
But to get to the transcendent state is more like solo climbing a great mountain. In this respect, a very good teacher can show you many helpful things that you must master to become a skilled climber. He or she can even tell you stories of their own adventures. But during this perilous climb you are strictly on your own. Like the fog of war, there is the fog of awakening to nirvana. When you are on your own trying to awaken to ultimate reality the path is much different. There is more confusion. At the same time you much be more concentrated than ever before. There can be no backsliding. It takes everything a person has and much more.