The answer to this question has to relate to the way in which this famous poem gives a list of characteristics that the reader or listener of this poem must possess if they are to be "a Man." Thus, related to your question, the reader can use this poem to give him or herself an idea of his or her own moral quality by using the list of characteristics as a kind of tick-box approach of how "moral" they are. What is interesting about this poem is that, even though it was written over a hundred years ago, the list of such qualities of integrity, honesty and valour still remain just as relevant today as they did all those years ago. Consider the following list:
If you can dream - and not make dreams your master;
If you can think - and not make thoughts your aim;
If you can meet with Triumph and Disaster
And treat those two impostors just the same;
If you can bear to hear the truth you've spoken
Twisted by knaves to make a trap for fools,
Or watch the things you gave your life to, broken,
And stoop and build 'em up with worn-out tools:
Such qualities are still just as important for people today, and arguably even more important as we seem to be living in a world where moral foundations are slowly being eroded away. To not allow our dreams to be our "master" and to be able to meet both "Triumph and Disaster" with perfect equanimity and to see them for the "impostors" that they are gives us the kind of list of qualities that allow us to assess our own moral integrity as readers of this poem.
Kipling shows that this is no idle game of “what-if.” In fact, all along this has been a guide to success, to achieving any dream imaginable. Kipling suggests that a person with the right virtues is capable of achieving anything he dreams.
The insight offered by the poet can be summarized in brief as: remain humble, avoid extremes, and enjoy the joys of life at every opportunity. Rise above the fray and find goodness in even the darkest circumstance!