Imam Khomeini, the late leader of the Islamic Republic defined through his theological works that Islam's attention to material life is because it can serve the spirituality. Spiritualities are the criteria.
According to Imam, al the differences among human beings are rooted in the rebellion of the 'self'.
If you are not purified, you will face rebellion of the 'self'.
So long as you are not purged, knowledge will be dangerous for you and the most dangerous thing for you will be a high position.
This may lead you to annihilation in this world as well as in the next world.