Initially it seems that, no ordinary man can show us the right way. We feel that we are atleast better that the multitudes who did not even begin their search for realization. So we feel that, only a realized soul, one who is somehow special, can lead us. So most of the quests for realization begin with a search for the Guru. The goal is clear: the Guru, or the Prophet, can lead us by some kind of magic. (This thought is also echoed in the last pages of the The Serpent and the Rope by Raja Rao.)
After some time, it also becomes apparent that, a realized soul cannot show a man the right way, if the man is unwilling to listen, or see things with an open mind. If one realized soul cannot show a man the right way, another realized soul cannot. This is because, no realized soul is greater than another.
It also become apparent that, when a man is willing to see the point and is doing effort to search for the truth, he does not need a realized soul to show him the right way. The right way manifests itself, as it was before him all the time. The moment a man is willing to search for the truth, there comes a time when his veil of ignorance automatically falls off. A realization dawns that a Guru is not doing some magic, but helping to remove the veil.
The where the purpose of a Guru is to just quicken the process. A Guru can reduce the amount of time a yearning soul has to spend in the searching. The purpose of Ishwara is also similar. As Ishwara has control on Maya, He too quicken the process. When I say an Ishwara, I mean the different manifestations of higher powers. They could be from the six Indian theistic schools. Or, they could be the Judeo-Christian-Islamic God.
Hence the sayings of Vivekananda: God is very merciful to those whom He sees struggling heart and soul for spiritual realization. But remain idle, without any struggle, and you will see that His grace will never come.
So, once we understand all this, we have a couple of questions:
What is the right thing for an ordinary man to do with respect to his realization: Should he search for a Guru or not? Should he pray to Ishwara or not?
What is the right thing for an ordinary man to do for the realization of his peers? Should he give them the insights he got? If so, how is he to know whether they are right or wrong? Should he correct them when he feels they are wrong? How does he know for sure whether he is right or wrong? from Plato: What is Good and What is bad, do we need someone to tell us Phaedrus?
What is the right thing for a realized man to do? Is this a trick question? A realized man is beyond right and wrong. What can a realized man do for others' realization? Just guide them, if he wants to.
The Maya of a person can be removed only by Ishwara. Can the Avidya of a person can be removed by a Guru? Possibly. The distinction between Maya and Avidya is possibly quite subtle, as it has caused considerable discussion among the disciples of Sri Adi Sankara. So I will not confuse the picture by posting on them now.