This path of self-reformation leading to Allah Ta‘ala is extremely sensitive. Therefore, it is necessary for one to have a spiritual guide who is completely acquainted with the path. At times, a person does not understand the limits and begins to continuously grieve over his past sins to such an extent that he loses hope. This then becomes an impediment and barrier for him to progress. Therefore, it is necessary for one to refer to a spiritual guide.
(Malfoozaat Hakeemul Ummat 23/378-379)