It is Obligatory To Be Acquainted With The Path of The Believers In Detail And That of The Criminals In Detail- By Imaam Ibnul Qayyim
In The Name of Allaah, The Most Merciful, The Bestower of Mercy
Imaam Ibnul Qayyim (rahimahullaah) said:
The people are four categories in relation to this subject matter [i.e. regarding their knowledge of the path of the believers and that of the criminals]
The First Group: They are those who know the path of the believers and that of the criminals in detail- in both knowledge and action. They are the most knowledgeable amongst the creation.
The Second Group: They are those to whom both paths are invisible and as a result they are like animals; so when the path of the criminals is presented to them they follow it.
The Third Group: They are those who concern themselves with [seeking] knowledge of the path of the believers and not its opposite; they only know [the path of the criminals] by way of its opposition to the [path of the believers] and in a general manner. They know that whatever is in opposition to the path of the believers is falsehood; even though their knowledge of such an affair is not detailed.
The Fourth Group: They know the path of evil, Bidah and Kufr in detail, but their knowledge of the path of the believers is general. This is the situation of many of those who concern themselves with the statements of the previous nations and that of the people of bidah- they are acquainted with [these affairs] in detail, but not the details of that which the Messenger [sallal-laahu-alayhi-wasallam] came with; rather they are acquainted with it in a general manner even though they may know some of its affairs in detail. Whoever examines their books will see that.
To be continued InShaaAllaah
[Source: Al-Fawaa’d pages 167-180…abridged and slightly paraphrased]