Imam explained that they seek to bring material gains under the service of spirituality. While the religions pay heed to the material and the world, they attract people towards spirituality and liberate them from the darkness of the material at the same time.
Islam's attention to material life is because it can serve the spirituality. Spiritualities are the criteria.
All the differences among human beings are rooted in the rebellion of the 'self'.
Those who seek to train others in this world should first purge and purify themselves.
Imam Khomeini stressed that 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.
According to Imam's thinking, the teaching of the Book and Wisdom will be impossible unless purgation comes first. You should purge your 'selves' from all contaminations. The worst one is the contamination of the 'self' with selfish and animal desires.