Sufi philosophy

Rooh ( Soul )
soul never dies and sufi mostly believe in a strong soul. you can make your soul strong through the practice and that practice you can get through the teaching of your pir. if you make your soul strong according to the teaching of Islam then you can get on the way which leads to Allah.

Fanaa
The nature of fanaa consists of the elimination of evil deeds and lowly attributes of the flesh. In other words, fanaa is abstention from sin and the expulsion from the heart of all love other than the Divine Love; expulsion of greed, lust, desire, vanity, show, etc. In the state of fanaa the reality of the true and only relationship asserts itself in the mind. One realizes and feeds that the only real relationship is with Allah Ta'ala fanaa means to destroy your self. if you destroy your self in the love of allah then that fanaa will convert into entire life means abdi zindgi. and for that one you have to destroy your will and yourself on the will of allah

Baqaa
Inayat Khan writes in his book A Sufi message of spiritual liberty

The ideal perfection, called Baqa by Sufis, is termed 'Najat' in Islam, 'Nirvana' in Buddhism, 'Salvation' in Christianity, and 'Mukhti' in Hinduism. This is the highest condition attainable, and all ancient prophets and sages experienced it, and taught it to the world.Baqa is the original state of God. At this state every being must arrive some day, consciously or unconsciously, before or after death. The beginning and end of all beings is the same, difference only existing during the journey.

Perfection is reached by the regular practice of concentration, passing through three grades of development: Faná -fi-Shaikh, annihilation in the astral plane, Faná-fi-Rasul, annihilation in the spiritual plane, and Faná-fi-Allah, annihilation in the abstract.After passing through these three grades, the highest state is attained of Bá qi-bi-Allah, annihilation in the eternal consciousness, which is the destination of all who travel by this path.