Achaemenid dynasty (648–330 BCE) Zoroastrianism developed the abstract concepts of heaven, hell, personal and final judgement, all of which are only alluded to in the Gathas. ''Yasna'' 19 (which has only survived in a Sassanid dynasty (226–650 CE) ''Zend'' commentary on the ''Ahuna Vairya'' invocation), prescribes a Path to Judgement known as the ''Chinvat Peretum'' or ''Chinvat Bridge'' (''cf:'' Al-Sirat in Islam), which all souls had to cross, and judgement (over thoughts, words, deeds performed during a lifetime) was passed as they were doing so. However, the Zoroastrian personal judgement is not final. At the end of time, when evil is finally defeated, all souls will be ultimately reunited with their Fravashi. Thus, Zoroastrianism can be said to be a universalist religion with respect to salvation.
In addition, and strongly influenced by Babylonian and Akkadian practices, the Achaemenids popularized shrines and temples, hitherto alien forms of worship. In the wake of Achaemenid expansion, shrines were constructed throughout the empire and particularly influenced the role of [[Mithra]], Aredvi Sura Anahita, Vahram and Tishtrya, all of which, in addition to their original (proto-)Indo-Iranian functions, now also received Perso-Babylonian functions.
Although the worship of images would eventually fall out of favour (and be replaced by the iconoclastic fire temples), the lasting legacy of the Achaemenids was a vast, complex hierarchy of Yazata (modern Zoroastrianism's Angels) that were now not just evident in the religion, but firmly established, not least because the divinities received dedications in the Zoroastrian calendar, thus ensuring that they were frequently invoked. Additionally, the Amesha Spenta, the six originally abstract terms that were regarded as direct emanations or aspects or 'divine sparks' of Ahura Mazda, came to be personified as an archangel retinue.