Those under the dominion of their evil inclinations should know well that they are in the dark. But the truth is that most often they cannot see this. They don’t realise they are in the dark. It takes a person who was already gone through the darkness and come out, to know what the darkness is all about. They are also most suited to be able to help others out of that darkness.
The Ramchal gives us a powerful comparison of a person who finds himself in a maze and needs to find his way somewhere. It is only someone who has successfully reached the goal who can best advise others on how to get to the desired goal.
Of course – only someone humble enough to accept the advice of the the other who has already achieved the goal, can himself be successful in reaching that same – successful – goal.
To others, they will always remain behind – walking in the dark.