Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) once mentioned:
The path of deen and the path leading to the true love of Allah Ta‘ala will only be understood in the company of the Ahlullah (i.e. those who have the true love of Allah Ta‘ala and the correct understanding of deen). Though the kitaabs of deen contain the laws and aadaab (etiquettes) of Islam, however through merely studying the kitaabs one will not succeed in acquiring the true understanding and essence of deen. One will be in need of the guidance of a spiritual guide who will demonstrate the practical application of deen to him. This principle is not confined to deen and the matters of deen. Instead it also applies to worldly matters. One fully understands that by merely studying medical journals and textbooks one will not succeed in acquiring sound health, rather one is in need of the guidance of a qualified, expert physician to guide him in acquiring good health. (Malfoozaat Hakeemul Ummat 4/100)
Source: Ihyaauddeen.co.za