There are six stages to knowledge: Firstly: Asking questions in a good manner. Secondly: Remaining quiet and listening attentively. Thirdly: Understanding well. Fourthly: Memorising. Fifthly: Teaching. Sixthly- and it is its fruit: Acting upon the knowledge and keeping to its limits.
Ibn Qayyim Al-JawziyyaThe heart becomes sick, as the body becomes sick, and its remedy is al-Tawbah (repentance) and protection [from transgression]. It becomes rusty as a mirror becomes rusty, and its clarity is obtained by remembrance. It becomes naked as the body becomes naked, and its beautification is al-Taqwa. It becomes hungry and thirsty as the body becomes hungry, and its food and drink are knowledge, love, dependence, repentance and servitude.
Ibn Qayyim Al-JawziyyaThe soul will never become pious and purified except through undergoing afflictions. It is the same as gold that can never be pure except after removing all the base metals in it.
Ibn Qayyim Al-Jawziyya