Is Sufism the same as monasticism? Do Sufis withdraw from the world?

Islam does not permit monasticism; Tasawwuf calls a person to live fully in the world, as a good son, a good father, a good husband, neighbour, and employee, not to retreat from it.

There is a major difference between a monk and a Sufi. Islam is a complete code of conduct and does not allow withdrawal from society. The purpose of creation as mentioned by Allah is to worship Him: “And I (Allah) have not created the jinn and mankind except that they should worship Me (alone).” [Qur'an, adh-Dhariyat 51:56]

Allah has also entrusted the believers with their families. So Tasawwuf promotes living a complete life: being good in every role, son, father, husband, neighbour, employee, businessman, and carrying out worldly affairs to the best standard Islam defines. The Companions are the proof: they earned livings, married, and supported families, and their way was not about denying the rights of the body or avoiding worldly affairs.