To answer this question about masters, first we need to know what a master is.
Who is Qualified to be Called a Spiritual Master?
In spirituality, the word master means "a worker or artisan qualified to teach apprentices." That is, they are a teacher, a helper, not a tyrant or authority to be worshipped.
In old traditions, and even today in some Asian traditions, the words "master" and "guru" were used out of respect and politeness, just as we use the words "teacher" or "guide." Unfortunately, modern people have corrupted the word master with many implications and meanings that are harmful.
Properly defined, a master is the innermost being of a human being who has created the soul: the solar bodies that give consciousness in the internal worlds, and immortality. That is, they are awake and active in the astral, mental, and causal planes. And the title of master belongs to the inner Being, not the terrestrial person.
"And, behold, one came and said unto [Jesus], Good master, what good thing shall I do, that I may have eternal life? And he said unto him, Why callest thou me good? there is none good but one, that is, God." —Jesus, in Matthew 19
"But be not ye called Rabbi [master]: for one is your Master, even Christ; and all ye are brethren. And call no man your father upon the earth: for one is your Father, which is in heaven. Neither be ye called masters: for one is your Master, even Christ." —Jesus, in Matthew 23
"In this day and age, everybody wants to be a master. Notwithstanding, we state that there is only one master, this is the inner Christ, which enlightens every human being who comes into the world. Thus, only Christ is the master. Only the resplendent “I Am” is the master." —Samael Aun Weor, The Major Mysteries
Although many people claim to be "masters," the truth is that the terrestrial person is only a terrestrial person. The only one who can be a master is the Innermost, Atman, the Father, Chesed.
The initiates know that when they call a person "master," they are not addressing the physical person, but the innermost being that is inside of them. But naive students who have their consciousness asleep do not understand this, and mistakenly believe it is the terrestrial person who is "a master."
“It beseemeth not a man, that God should give him the Scriptures and the Wisdom, and the gift of prophecy, and that then he should say to his followers, ‘Be ye worshippers of me as well as of God;’ but rather, ‘Be ye perfect in things pertaining to God, since ye know the Scriptures, and have studied deep.’ God doth not command you to take the angels or the prophets as lords.” —Koran 3:9
"The value of the human person which is the intellectual animal called human being is less than the ash of a cigarette. However, the fools feel themselves to be giants. Unfortunately, within all the pseudo-esoteric currents a great amount of mythomaniac people exist, individuals who feel themselves to be masters, people who enjoy when others call them masters, individuals who believe themselves to be Gods, individuals who presume to be saints. The only one who is truly great is the Spirit, the Innermost. We, the intellectual animals, are leaves that the wind tosses about... No student of occultism is a master. True masters are only those who have reached the Fifth Initiation of Major Mysteries [Tiphereth, the causal body]. Before the Fifth Initiation nobody is a master." —Samael Aun Weor, The Perfect Matrimony
"You [if you have reached levels of initiation] are not the master, you are only the sinning shadow of He who has never sinned. Remember that only your internal Lamb is the master. Remember that even though your internal God is a Hierarch of fire, you, poor slug, are only a human being and as a human being you will always be judged. Your internal Lamb could be a planetary God, but you, poor slug of the mud, do not forget, always remember that you are only the shadow of your God. Poor sinning shadow..! Do not say “I am this God” or “I am that master,” because you are only a shadow that must resolve to die and be slaughtered in order not to serve as an obstacle for your internal God. It is necessary for you to reach supreme humbleness." —Samael Aun Weor, The Aquarian Message
Can We See if Someone is a Master?
The Gnostic scripture "The Acts of Peter and Paul" relates the tale of Simon Magus, who by all appearances was a great master and had many devoted followers. About him, Samael Aun Weor said:
"Evilness is so fine and delicate that even the Master H. P. Blavatsky firmly believed that Simon the Magician was a master of the White Lodge. Master Huiracocha also believed that Simon the Magician was a great Gnostic master, and he told us that everything that "Papus" and other authors have taught in the past years about magic was taken from Simon the Magician. The only one who was not mistaken with respect to Simon the Magician was Dante Alighieri in his Divine Comedy.
"Dante called the disciples of Simon the Magician SIMONIACS. The Romans built statues in honor of him, with the inscription, "Simoni Deo Sanctu." However, when attentively studying the books of Simon the Magician, apparently there is nothing that can be condemned as black magic. Evilness is so fine in the world of the mind... Evilness is so delicate and subtle in the plane of cosmic understanding that in reality a lot of intuition is needed in order not to be cheated..." —Samael Aun Weor, Treatise of Sexual Alchemy
That is why Samael Aun Weor gave this strict instruction:
"This is why we advise our disciples not to follow anyone. Let our disciples follow their own Self. Each of our disciples has to follow their resplendent and luminous inner Being. Each one has to adore their own “I Am.” We beg, beseech, our disciples not to follow us. We do not want henchmen or followers. We have written this book so that you, our friends, listen to your own internal master, your resplendent “I AM.” The Innermost is your master: follow Him. First, take heed that none of the many false avatars who appear during these times deceive you, for many impostors appear in these times and deceive others. Second, take heed of sexual temptations. Third, do not ever attend spiritual centers; the mediums-channelers can easily lead you astray from the path. Many disciples have fallen horribly due to these three dangerous reasons. Flee from these three treacherous dangers so that you may not lose your initiations and degrees." —Samael Aun Weor, The Major Mysteries
“I do not follow anyone; therefore no one should follow me.” —Samael Aun Weor, Practical Astrology
Do You Need a Spiritual Master?
There are always many people humbly proclaiming themselves to be masters. Sadly, modern people mistakenly believe they need to follow a "master" in the physical world. This is a grave error, propagated by those who benefit from the mistake.
Avoid all those who say, “I am a master...” - Samael Aun Weor
You do not need those "masters" to walk the path. In fact, quite the opposite is true: by submitting to yourself to some external authority, you no longer seek to hear the voice of the real master, who is within you.
"There is a need to search for a guru in order for him to guide us along this internal and delicate way. The guru must be searched for within, in the profundity of the consciousness... Each disciple must search for the master inside, inside, inside. The master is found in the profundity of our consciousness. If you want to search for the master, abandon all bookish erudition and pseudo-spiritual schools. The master appears when the disciple is prepared." —Samael Aun Weor, Igneous Rose
"...in this day and age, it is very dangerous to just simply follow someone. What is best is to seek the Inner Master. The best thing is to follow our “I Am.” The best thing is to learn how to travel in the Astral Body in order to visit the temples of the White Lodge and to receive the teachings directly in the temple...
"Authentic degrees and authentic white initiations are received in the consciousness. These initiatic ceremonies are performed within the superior worlds. Initiations are intimate realizations of the consciousness, which must not be revealed, or spoken about. No one can grant initiations to anyone. Initiation is attained through life itself. In this day and age, everybody wants to be a master. Notwithstanding, we state that there is only one master; this is the inner Christ that enlightens every human being who comes into the world. Thus, only Christ is the Master. Only the resplendent “I Am” is the Master." —Samael Aun Weor, The Major Mysteries
"Initiation is something very intimate, very secret, very divine. Avoid all those who say, “I have so many initiations, so many degrees.” Avoid all those who say, “I am a master of Major Mysteries; I have received so many initiations.” Remember, dear reader, that the “I,” that the personality does not receive initiations. Initiation is a matter for the Innermost; it has to do with the consciousness, with the very delicate things of the Soul. One must not go about speaking of these things. No true adept would ever use phrases like, “I am a master of the White Lodge,” “I have such-and-such degree,” “I have so many initiations,” “I have these powers,” etc." —Samael Aun Weor, The Perfect Matrimony
"Initiation is neither bought nor sold. Avoid those schools that give initiations by correspondence. Avoid all those who sell initiations. Initiation is something very intimate to the Soul. The “I” does not receive initiations. Therefore, those who say, “I have so many initiations,” “I have such-and-such degrees,” are liars and fakes, because the “I” does not receive initiations or degrees. There are nine Initiations of Minor Mysteries and five important Initiations of Major Mysteries. The Soul is the one who receives the initiations. This is a very intimate matter; something that one must not go about speaking of, nor something that must be told to anyone. Indeed, all the initiations and degrees that many schools of the physical world confer have no value whatsoever in the superior worlds, because the masters of the White Lodge only recognize the legitimate initiations of the Soul as genuine. These are completely internal. The disciple can ascend the nine arcades, pass through all the nine Initiations of Minor Mysteries, without having worked in the Arcanum A.Z.F. (Sexual Magic) . Nevertheless, it is impossible to enter the Major Mysteries without Sexual Magic (the Arcanum A.Z.F.)." —Samael Aun Weor,, The Perfect Matrimony
Here is what Jesus said about "masters":
"The scribes and the Pharisees sit in Moses' seat: All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not. For they bind heavy burdens and grievous to be borne, and lay them on men's shoulders; but they themselves will not move them with one of their fingers. But all their works they do for to be seen of men: they make broad their phylacteries, and enlarge the borders of their garments, And love the uppermost rooms at feasts, and the chief seats in the synagogues, And greetings in the markets, and to be called of men, "master, master." But be not ye called master: for one is your Master, even Christ; and all ye are brethren. And call no man your father upon the earth: for one is your Father, which is in heaven. Neither be ye called masters: for one is your Master, even Christ." —Matthew 23
Signs of a False Master
The easiest way to separate pure from impure is on the basis of chastity: a genuine master knows that the path of liberation requires sexual transmutation. However, that is not foolproof: there are many black magicians who preserve their sexual energy. Yet, they do not eliminate the ego. Read Treason by Samael Aun Weor to learn more.
"The disciple who wants to enter the straight, narrow, and difficult path that leads us to the Light has to withdraw from all spiritual schools. Those schools are filled with “sublime crimes.” Those schools are golden cages filled with “very beautiful poisonous vipers.” Mystical evilness is very abundant in those schools. The worst crimes registered in the penal code are committed under the shelter of the divine phrase “Universal Fraternity.”... We have known horrible cases. I.e. we knew the case of a certain hypocritical pharisee who passed himself off as Jesus Christ... later he alleged that he was uniting all the schools, orders, sects, creeds, and lodges within a universal fraternity—and he was the center of it all, naturally. We knew about another subject who took the name of K. H. in order to declare that he was an Avatar, and that he should reunite all the schools under his scepter. All these types of opportunist subjects usually found black lodges under the shelter of the beautiful phrase “Universal Fraternity.”... Therefore, we advise our disciples to be very careful, it is better to withdraw from these types of ladies and gentlemen, because they are dangerous and deceitful." —Samael Aun Weor, The Major Mysteries
There are some "gnostics" — even famous ones — who reject the Eucharist: the consumption of blessed bread and symbolic wine (grape juice). About this, Samael Aun Weor wrote:
"One night, I invited a gentleman to the holy Gnostic Eucharist. Instead of the consecrated wine, the gentleman drank water; that is to say, that gentleman flatly rejected the blood of redemption. Indeed, the tree is known by its fruits, and that fruit is black... No white magician would ever reject the blood of redemption. With this act in this moment of the twentieth century, that emissary of the black lodge of Aquarius committed the greatest of all infamies: rejecting the blood of the martyr of Golgotha...
"The Holy Eucharist should be practiced in the houses of all our Gnostic brothers and sisters, and not only in brick, stone or concrete temples." —Samael Aun Weor, Secret Notes of a Guru
Some people who claim to be masters say that they must announce their mastery "for the good of humanity." About this, Samael Aun Weor said:
"To send more prophets to the Earth is useless, since this humanity mortally hates the prophets. Therefore, no one can save this humanity. No one can correct this humanity. This human evolution is a complete failure." —Samael Aun Weor, The Aquarian Message
Signs of a Real Master
There is only one way to know definitively if someone is a master of the white lodge: awaken your consciousness in the superior worlds and investigate them there. Anything less than that is unreliable. Yet, there are some rather obvious indicators in the physical world:
"The authentic master never boasts of being a master... An authentic guru does not go around boasting about it. The authentic guru is the Inner Christ. A true master goes around everywhere anonymously and unknown. He does not exhibit his deeds or powers, and is filled with modesty. A true master is before anything else an upright citizen. The authentic master is never an intellectual, since the intellect is an animal function of the human “I.” The true master is like a child, pure, holy, simple, and natural. The true master is the Inner Christ “that is the true Light, which lightens every man that comes into the world” [John 1:9]." —Samael Aun Weor, The Major Mysteries
"...the authentic female enlightened masters never go around boasting about it. The true disciples and masters are those who know how to consciously travel in their astral body. The male and female devotees who remember their past lives and who can astrally attend the temples of mystery are true enlightened beings, yet they never go around boasting about it; these are the ones who really know." —Samael Aun Weor, The Major Mysteries