In the Old Testament, the story of Adam and Eve tells us of the devolution of the first human beings from unity consciousness to the bondage of the gunas. The main key to their fall was their pride of being equal to the Source of the unified field. Thus, they disobeyed the rule by eating the forbidden fruit.
Along with pride came the desire to indulge in the senses. Since they thought they were gods, then they can get anything they wanted in the phenomenal world. By doing so, they knowingly put their spirit in bondage to matter.
