Eusebeia (Greek:εὐσέβεια, from eu meaning "well", and sebomai meaning "reverence", itself formed from seb meaning sacred awe and reverence especially in actions) is a Greek word abundantly used in Greek philosophy as well as in the New Testament, meaning inner piety, spiritual maturity, or godliness. John 21:1 Jesus Appears to His Disciples--Alessandro Mantovani: the Vatican, Rome. ...

The first recorded usage of the word dates to Homer, circa 1000 BCE. The Homère Caetani bust at the Louvre, a 2nd century Roman copy of a 2nd century BC Greek original. ...

The word was the used in Classical Greece where it meant "personal piety in the fulfillment of human relationships". It also expressed the act of concretely and outwardly fulfilling worshipping acts towards Greek gods (gifts, sacrifices, public devotions), and by extension to honour the gods by showing proper respect to elders, masters, rulers and everything under the protection of the gods. This article describes the ancient classical period: for the classical period in music (second half of the 18th century): see Classical music era. ...

For Platonists, "Eusebeia" meant“right conduct in regard to the gods.” For the Stoics, “knowledge of how God should be worshipped.” Platonic idealism is the theory that the substantive reality around us is only a reflection of a higher truth. ... Stoicism is a school of philosophy commonly associated with such Greek philosophers as Zeno of Citium, Cleanthes, or Chrysippus and with such later Romans as Cicero, Seneca, Marcus Aurelius, and Epictetus. ...

Progressively, and within the wider Hellenistic world, or koine, Eusebeia came to designate "inner piety", or spirituality, a duty inwardly due to God. The literal meaning of the Greek word koine (κοινή) is common. It is used in several senses: Koiné Greek (Κοινή Ἑλληνική), a Greek dialect that developed from the Attic dialect (of Athens) and became the spoken language of Greece at the time of the Empire of Alexander the Great. ...

"Eusebeia" was adopted by Christianity to describe the awasome respect due to God and his worship. It is often translated as "godliness" in the New Testament. Christianity is a monotheistic[1] religion centered on Jesus of Nazareth, and on his life and teachings as presented in the New Testament. ...

Zodhiates says that:

"When eusébeia is applied to the Christian life, it denotes a life that is acceptable to Christ, indicating the proper attitude of the believer toward Christ who has saved him. It is both an attitude and a manner of life." Zodhiates

"Divine power has granted to us everything pertaining to life and godliness (eusébeia), through the true (full, personal, experiential) knowledge of Him Who called us by His own glory and excellence." Peter (2 Pet 1:3)