Why did Imam advise to perform deeds in pure forms for divine sake?

How Imam Khomeini does sheds lights on characteristics of a true believer?

Human being miserably fails to grasp the extent of his own small world, Imam Khomeini explained

Imam Khomeini through his theological works explained that human being, a creature crawling on one of the smallest planets miserably fails to grasp the extent of his own small world, whose sun cannot be compared with far greater suns of innumerable galaxies.

Imam Khomeini explained the domain of the Hereafter

Imam Khomeini through his theological works explained at the time of entering the other world, that is, the domain of the Hereafter, the first stage of which is Barzakh.

Imam Khomeini: The combatant and honorable nation of Iran has been prepared to sacrifice everything ...

Sahifeh-ye-Imam. V 15. P 223

Imam khomeini a divine voice and friend to god the almighty

Alex Broudi, a British journalist

One of the moral maladies is maltreatment of other people, Imam Khomeini explained

Imam Khomeini through his theological works explained that one of the moral maladies is the maltreatment of the people of his household, his neighbors, his colleagues and others around him.

Imam Khomeini explained how the secrets of this world are to be unveiled

Imam explained how human are mistaken to consider the world of the hidden realities, where the secrets of this world are to be unveiled and your deeds are to be disclosed,