Question Summary:
Do Sufis believe in Hulul (incarnation) and Ittihad (unification)?

Question Detail:

Can you give a response to this accusation raised by a Salafi Alim?Assalaamu Alaikum Sheikh, May Allah bless you. I recently was going through a website and then it had somethings written against Tasawwuf. I do not by any means want to create divisions in the Ahlus Sunnah wal Jammah. I didn't really want to ask this question at first but then I started having doubts a little. So please clarify it for me ya sheikh.  islamqa.info/en/1087
I have provided the link above. The answerer talks about how Tareeqa is innovation and say that there are deviant ideas of kufr in the books of sufism. Please help! 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
 
Assalāmu ‘alaykum wa rahmatullāhi wa barakātuh
 
“Sūfism” or “Tasawwuf” is the method of purifying the inward (tazkiyat al-bātin), which is something required in the Sharī‘ah[1]. It is a discipline developed by some of the accepted scholars of the Salaf, including Ibrāhīm ibn Adham (ca. 100 – 162 H), Ma‘rūf al-Karkhī (d. 200 H), Sarī al-Saqatī (ca. 160 – 253 H) and Junayd al-Baghdādī (ca. 220 – 297 H).[2]
While there were some wrong beliefs and practices associated with certain claimants of Tasawwuf, these were denounced by the leading Sūfī imāms, and are not considered essential aspects of the discipline of Tasawwuf.
One will find many hadīths that are fabricated and many narrations in books of Tafsīr that are baseless. This does not mean we throw out the science of hadīth or tafsīr. Similarly, merely because of some incorrect beliefs and practices found amongst some groups of Sūfīs, we cannot reject the entire discipline of Tasawwuf.
The beliefs of hulūl (incarnation) and ittihād (union) are misguided beliefs. If any person in the name of Tasawwuf subscribes to these beliefs, his claim to represent Tasawwuf is rejected. The assertion that these beliefs are found in mainstream books of Tasawwuf is incorrect. One may read the Risālah of al-Qushayrī (d. 465), al-Ihyā of al-Ghazālī (d. 505), Futūh al-Ghayb of ‘Abdul Qādir al-Jīlānī (d. 561), al-Maktūbāt of al-Sirhindī and other famous works of Tasawwuf without finding a trace of these false beliefs.
It is important for a person seeking a spiritual guide (murshid) to first ascertain that he is a muttabi‘ al-sunnah (adherent of sunnah). That is, he is a person of sound ‘aqīdah who adheres to the beliefs of Ahlus Sunnah wa l-Jamā‘ah and is not a person of innovation.[3]
To gain a better understanding of Tasawwuf, you may read Sharī‘ah and Tarīqah: Inseparable and Indivisible by Mawlānā Zakariyyā al-Kāndehlewī, available at the following link:
http://attahawi.files.wordpress.com/2011/02/shariah-and-tariqah-inseparable-and-indivisible.pdf
And Allah Ta‘ālā Knows Best
Zameelur Rahman
Student Darul Iftaa
UK
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net