The primary purpose of Tasawwuf
The terms Tasawwuf (Sufism), Tareeqat (طریقت), Sulook (سلوک), Ihsan (احسان), all refer to the same thing and are inter-changeable. The primary aim of Tasawwuf is not merely doing Zikr (remembrance), for example, some people think that if we do bayt (بیعت) with a Shaykh, he will tell us some Tasbeehat (تسبیحات) to recite. Some other people think that the purpose of Tasawwuf is to learn how to do Tawez (تعویذ), and that the Shaykh will teach us how to treat physical and social ills with Tawez. Tasawwuf has nothing to do with learning to write Tawez and spiritual treatments. In fact, even Zikr is not the primary purpose of Tasawwuf. Similarly, some other people think that the purpose of Tasawwuf is that a person becomes a monk, goes to some remote place and meditates there, and does Mujahidah (spiritual effort). None of these is the primary purpose of Tasawwuf though some of these are ways to achieve its primary purpose.
What then is the primary goal of Tasawwuf? The Noble Qur’an has pointed towards the primary goal of Tasawwuf in Surah Ash-Shams;

“I swear by the sun and his broad light, … and by the soul, and the One who made it well, then inspired it with its (instincts of) evil and piety, success is really attained by him who purifies it, and failure is really suffered by him who pollutes it.” (91:1&7-10)

And in the Noble Qur’an, while describing the aims of sending the Holy Prophet ﷺ, Allah Ta’ala says;

“We have sent in your midst a messenger from among you, who recites to you Our verses, and purifies you, and teaches you the Book and the wisdom, and teaches you what you did not know.” (2:151)

In this verse, Allah Ta’ala has listed ‘Tazkiyah’ (purification) as a separate purpose from teaching of the Noble Qur’an and teaching of wisdom.
Tazkiyah literally means purifying something. There are many commandments of Shariah which pertain to a person’s body, as in they are carried out physically. Some of them are DOs (اوامر) for example, pray Salah, observe fasting, give Zakat, perform Hajj, etc., and some of them are DON’T’s (نواہی), for example, do not tell a lie, do not do Gheebat (backbiting), do not drink alcohol, do not steal, do not commit robbery, etc.
In exactly the same way, there are many commandments of Shariah which pertain to a person’s mind, or inner self. Some of these are DOs called Awamir (اوامر). Developing these good moral values is Wajib (necessary) and a person’s Deen doesn’t become complete unless he develops these good moral values. For example, it is Wajib (necessary) to perform Shukr (being thankful to Allah Ta’ala for His blessings upon us), observing Sabr (patience, steadfastness) if something undesirable happens, observing Tawakkul (placing one’s complete trust in Allah Ta’ala), developing Tawazu (humility, believing others to be better than oneself), and developing Ikhlas (sincerity of intention, meaning whatever a person does, he does it solely with the intention of seeking Allah Ta’ala’s pleasure and approval). Developing Ikhlas is Wajib as no act of worship is acceptable without Ikhlas. All these good moral values such as Shukr, Sabr, Tawazu and Ikhlas are called Akhlaq-e-Fazilah (اخلاقِ فاضلہ) and trying to develop them is Wajib (necessary).
Similarly, there are some bad or undesirable moral values in our minds or inner-self which are Haraam (impermissible) and we must try to remove them from our minds. These are called Akhlaq-e-Razilah (اخلاقِ رذیلہ). If these traits are present in us, then a person has to try to suppress and attenuate them so that they do not lead a person to commit sinful acts. The examples of such undesirable mental traits are Takabbur (تکبّر) (grandiosity, believing oneself to be superior to other people), Hasad (حسد) (envy, being jealous of the good things others have and wishing or making efforts that they lose them), Riya (ریا) (doing acts of worship with the intention of pleasing people, rather than pleasing Allah Ta’ala), and impatience (بے صبری) (not accepting what Allah Ta’ala has decided for us and keep complaining about fate), etc. Having the habit of becoming unduly or excessively angry without just reason is also one of these bad moral values. These bad moral values are as Haraam (impermissible) as committing a robbery or telling a lie.
In summary, there are some good or desirable moral values (Akhlaq-e-Fazilah) pertaining to our inner-self which it is incumbent upon us to develop, and there are some bad moral values (Akhlaq-e-Razilah) pertaining to our inner-self which we are required to attenuate and control. The role of a Sufi Shaykh is to inculcate and enhance the former, and attenuate and weaken the latter, in the minds of his spiritual pupils called Mureed (مرید).
Hazrat Thanvi (may Allah Ta’ala have mercy on him) further used to say that the aim of treating bad moral values is not to get rid of them completely, as many of these are natural instincts and it is not possible to do so. The idea is to keep opposing them through one’s thoughts and behaviours so much that they become so weak as if they do not exist anymore. This process of enhancing and further developing good moral values, and weakening and attenuating bad moral values, is called Tazkiyah and this is the primary goal of Tasawwuf.

The need for a Shaykh (spiritual guide)
However, usually it is not possible to obtain this internal purification without entering into a mentoring relationship with a Shaykh (spiritual mentor). If a person wants to develop expertise in any skill, he has to find a mentor who can teach him that skill. Even if a person wants to become an expert chef, he has to enter into the tutelage of an established chef. It requires a high level of skill to differentiate between different attributes of one’s inner-self, and to decide which of these attributes is desirable, and which one is undesirable. For example, Takabbur (grandiosity, believing others to be inferior to oneself) is Haraam (unlawful), and it is Wajib (necessary) to protect oneself from Takabbur, as it gives rise to many spiritual ills. However, there is another mental attribute which is self-respect. It is Wajib to develop self-respect, as disrespecting oneself intentionally is not allowed in Shariah. However, differentiating between these two, whether a person is doing something out of Takabbur or self-respect, is a very delicate matter. Only an expert on spiritual ills can differentiate between these two, and it is very difficult for a person to recognize these spiritual ills within himself.

Differentiating between self-praise and acknowledging Allah’s blessings
Similarly, praising oneself and bragging that “I am so great, I am this, I am that”, is a spiritual illness and is Haraam in Shariah. The term used for it in Tasawwuf is Ta’alli (تعلّی). Another superficially similar attribute is Tehdees-e-Naimah (تحدیثِ نعمت) which has been mentioned in the Noble Qur’an. It refers to acknowledging Allah Ta’ala’s blessings upon oneself.

“…And about the bounty of your Lord, do talk.” (3:11)

Superficially both are similar and if a person is saying something good about himself, it is not easy to differentiate whether it is out of Ta’alli or Tehdees-e-Naimah.
Once Hazrat Thanvi (may Allah Ta’ala have mercy on him) was giving a sermon from a mosque’s pulpit in Delhi in front of a large gathering of people. While delivering the sermon he said,

“Let me tell you something. You will only hear it from me and will not hear it from anyone else. I am saying this as Tehdees-e-Naimah that Allah Ta’ala has imparted this knowledge only to me.” After saying this Hazrat Thanvi RE became quiet for a moment, and then said, “Asthagfirullah (may Allah Ta’ala forgive me), Asthagfirullah, Asthagfirullah. What I just said that you will hear this only from me, and no one else, this is Ta’alli (boasting, bragging). I am praising myself, and I termed it Tehdees-e-Naimah. May Allah Ta’ala forgive me. Because I had committed this sin publicly, therefore, I also do my Taubah (repentance) publicly, and I beg Allah Ta’ala for forgiveness.”

Hazrat Thanvi RE then said, “first I boasted, and then I tried to make it look like as if I was trying to express my gratitude to Allah Ta’ala. Because I had committed this sin publicly, I also repent publicly that I made this mistake and I seek forgiveness from Allah Ta’ala.” Only someone who has crushed his ego completely, who knows how spiritual ills can manifest in a person’s speech or behaviour, and who is always critically evaluating his own behaviour, can admit his mistake publicly like this. This is why one needs a Shaykh (mentor) because it is extremely difficult to appreciate the difference between phenomena such as Ta’alli (self-praise) and Tehdees-e-Naimah (acknowledging Allah Ta’ala’s blessings) which seem so similar on the surface.
Similarly, Tawazu (humility, believing that other people are better than oneself) is a great moral attribute and is highly desirable. But there is another attribute in which some people disrespect themselves in front of other people. This is Haraam. Allah Ta’ala has made it Wajib (necessary) that we preserve our self-respect. We are not allowed to debase ourselves deliberately. However, differentiating between the two, i.e. being able to tell which behaviour is carried out because of Tawazu, and which is bordering on disrespecting oneself, is not easy and not everyone is able to do it.
Sometimes Tawazu (تواضع)(humility) can be confused with disrespecting oneself (ذلتِ نفس), and sometimes with ungratefulness (ناشکری). It is often not possible to tell them apart unless someone has undergone training for this by a Shaykh. One cannot learn this just by reading a book and then beginning to decide what is Tawazu and what is disrespecting oneself. One can learn this skill only through practical training in which one keeps observing a Shaykh’s behaviour and actions over a period of time, and keeps seeking guidance from him after informing him about one’s own behaviour. Only after going through that process can a person learn whether a particular behaviour or way of thinking is desirable or undesirable.

An example
I often give an example that if you ask the greatest philosopher, scholar, poet or orator to describe the scent of a rose in words so clearly that someone would be able to differentiate between the scent of a rose from the scent of a jasmine flower just by listening to them, then they will never be able to do so. The only way to differentiate between the scent of a rose and a jasmine flower is to smell them. There is no other way of telling the scents of these two flowers apart.
Similarly, if someone wants to define the good moral values of a person’s inner-self, it will be very difficult. For example, how can someone define Tawazu (humility) in words so that the reader can get a clear picture of what Tawazu looks like in real life? However, if you see a person with Tawazu, observe their behaviour, and start spending time in his company, then you will start developing Tawazu yourself. That is why spending time in the companionship of a Shaykh, telling them about one’s own spiritual weaknesses, and then acting on their advice, is an essential part of Tasawwuf. One cannot develop these good moral values just by talking or reading about them, these are developed only after crushing one’s ego in front of a Shaykh and then Allah Ta’ala showers His blessings.

The primary aim of Tasawwuf is improvement of inner-self
Anyway, it is not obligatory for a person to do bayt (بیعت) at a Shaykh’s hand. What is obligatory is self-improvement. When a person enters into a mentoring relationship with a Shaykh, the primary purpose of establishing that relationship is to develop good moral values (اخلاقِ فاضلہ), and get rid of or attenuate bad moral values (اخلاقِ رذیلہ). This is the primary aim.
Reciting Tasbeehat as in doing Allah’s Zikr (remembrance) is an aide to this process, but unless a person makes conscious efforts to conquer his bad moral values, Zikr alone is generally not sufficient. In fact, even the decision to perform Zikr and how much to perform, should also be made after seeking a Shaykh’s guidance. The primary aim is to purify one’s inner-self, and the way to do it is to keep informing the Shaykh about one’s thoughts and behaviour, and to keep modifying one’s thoughts and behaviour in view of Shaykh’s guidance, and to keep doing it for one’s entire life.

وآخر دعوا ان الحمد ﷲ رب العالمين