Allaah has protected the homeland of Islaam with the mujaahideen (those who fight jihaad) and He has protected the prescribed way of eemaan with the teachers. Since He, the Most High, says in His clear Book: It is not right for the Believers that all of them should go off to battle. Rather from every troop of them some of them should remain in order that they should attain knowledge in the Religion. That they should warn their people when they return to them so that they can beware of evil. [Soorah at- Tawbah (9):122]. So Allaah, the Perfect, placed the Believers into two groups. On one of them He has made it obligatory that they fight jihaad in His way. And upon the other one, He has made it obligatory that they attain knowledge of His Religion, in order that not all of them go off to fight jihaad. Because if they all went off to fight jihaad, then the prescribed laws would pass away and knowledge would pass away. Then it would not be possible for them to seek knowledge after that and so the unbelievers would therefore gain dominance over the Religion. Thus, Allaah has raised up high the levels of the two groups of people.