Answer
First, one should remain truthful about one's own level of realization.
Suppose you wish to purchase something. If you actually have the money, your desire is realistic. But if you do not have the money and merely imagine that you possess it, you are living in illusion.
Similarly, one should honestly recognize one's present realization of Krishna and continue progressing from that platform. Never pretend to possess realizations that one has not yet attained.
As for recognizing another person's advancement, one cannot judge merely by external appearances.
Observe how that person lives over time—how he conducts himself throughout the day.
People can easily maintain a favorable social image. They may appear extremely humble and saintly in public, while behaving very differently in private.
Therefore, do not judge based on occasional interactions.
A person's real character is revealed by observing how he consistently relates to:
Superiors.
Equals.
Subordinates.
A genuinely advanced Vaiṣṇava behaves with the same spirit of respect, humility, and devotion in all three relationships.
Someone may appear very humble before authorities while behaving harshly toward equals or subordinates. Such behavior reveals that the humility is merely external and motivated by social image.
True spiritual maturity is seen when a person's dealings are consistently Vaiṣṇava-like, regardless of whom they are interacting with.
Only by observing a person's conduct over an extended period can one recognize whether that person's respect for others genuinely comes from the heart rather than from a desire to maintain a favorable reputation.
