Age is irrelevant when it comes to being a teacher, advisor, a source of information, or a guide when one is disseminating truths; especially in regards to the absolute truth or the highest truth.

Srimad-Bhagavatam 1.1.2:

“…   The highest truth is reality distinguished from illusion for the welfare of all. Such truth uproots the threefold miseries. …”

Specifically, what is meant in regards to the Supreme Personality of Godhead.  If we reject disempowerment; and instead of training devotees to find security in the herd mentality; we train them to become critical thinkers, to be free from doubt and delusion, to act without hesitancy, and to become single-minded about living their lives as an offering to the Supreme Personality of Godhead; then the role of a spiritual authority will be fulfilled.

Of course, this can only be taught to those who want to learn these things, and such candidates are always a minority. 

One may preach pure bhakti everywhere in the sense of making it available everywhere, but threaded throughout the philosophy itself is the idea that bhakti is never really a scientific process for the masses; or for argument’s sake, let us say that Bhakti is never really a mass religion.  It seems that many people are not cognizant of this.  They take the messianic approach, and want to save the whole world.  Nevertheless, what is the main force driving this idea?

 Is it the personal experience of pure Krishna consciousness?  I do not think so.  

Years of observation of hundreds of my Godbrothers/Sisters, and followers of Srila Prabhupada, personal self-analysis, and processing the philosophy, has lead me to believe that the reason the majority of devotees latch onto the messianic approach with such enthusiasm is not the taste of Krishna consciousness itself.  It is the belief that by becoming “big” preachers, they will somehow oblige Krishna to save them; and of course, in some cases, touches of name, fame, and glory (what Srila Bhaktivinoda Thakura called “Subtle Sex Life”), with heady notions of seizing a page of Vaishnava history, is mixed in as well.

The messianic idea is there, and according to the Supreme Lord Himself, it will spread throughout the planet earth in the next 10,000 years.  Srila Prabhupada has said that this will happen, with or without your help, and all you have to do is participate.  The messianic approach is one of gradual change. If it takes 2,000 years, it will still have a Glorious run of 8,000 more years. This messianic spirit should have the following attributes: 

1. The preaching should be such that the goal of human life is clearly understood by all the various social, religious, and economic societies on earth.
2. The process of achieving the human goal of life should also be laid on the table for all to know; presented in a matter that all members of any society can understand it. Verses from the Scriptures of the Vedic, Jewish, Christian, and Muslim traditions state that the goal of life is identical, not different at all, and that should be emphasized.
3. The preaching should be such that the masses will at least obtain an appreciation of bhakti.
4. The preaching should be such that some of the persons who have an initial appreciation will actually take the steps to start practicing the scientific process of bhakti. (See essay “Bhakti is a Science”)
5. All who are practicing the process should understand that this process could take as short as a moment, and up to many life times. It all depends on the sincerity of a person.
6. For those who are “work in progress for many past life times” and those “work in progress that has started in this life”, the preaching should be to encourage them to finish in the current life. They should be recognized as devotes with more or less nitya sukriti assets.  Thus, they should be given accelerated facility, for them to get to the point, they left off in their past life, as soon as possible, and then to continue and finish their bhakti.
7. There will be a large majority of the population with no interest in executing bhakti. They will only have an appreciation for it.  Thus, the preaching should not kill this spirit.
8. There will be a large majority of the population with no appreciation for these truths. They will be more or less in an apathetic psychological state of mind.  Their only concern is that they have a job, earn money, and enjoy their current life in an environment where there is no war, persecution, hunger, violence and other similar undesirable things and dangers.  Security from violence from demonic natured human beings, will be their only other concern.  They will be happy just to live in a world that is a true civilization.  The preaching for them should be simply; this is matter and this is spirit, this truth and this is illusion, this is demonic and this is divine, this is in the mode of goodness, this is in the mode of passion, and this is in the mode of ignorance.
9. In order for the whole world to be under the care of saintly persons who are critical thinkers requires around two percent of the population. These individuals will have various degrees of advanced understanding regarding the scientific process of bhakti.  The heads of state, and the institutions administrating the governments, should be staffed with individuals who are able to distinguish the truth from illusion, and misconceptions.  For these persons the preaching should be of the most advanced, and for some the most intimate knowledge, of the process of bhakti.  Amongst this two percent of total population on earth, there will be those who are very close to obtaining the goal of human life, for it is extremely rare.  Thus, those who preach to them will also be rare.
10. The preaching should fit the current nature of the individual; otherwise, it will not have the upmost effect if it is too little or too much to be handled by the individual. Thus, the ability to discriminate, and critical thinking go hand in hand.
11. Preachers will be of three levels, neophyte, intermediate, and advanced. The common thread to all three levels, is that they cannot give anything they do not possess.  That would be cheating; which would ruin not only the preachee’s progress; it will ruin the preacher’s progress as well.
12. Another common attribute of all ‘critical thinking’ preachers should be that they are preaching because they desire to do the highest welfare work for humanity at large.