PIETY. The word occurs only once in KJV and ASV (1Tim.5.4): “Let them learn first to show piety at home.” RSV uses “religious duty,” NIV “put their religion into practice.” NIV has “piety” three times in Job (1Tim.4.6; 15:4; 22:4), where others use “fear” (of God) or (once in rsv) “integrity.”
International Standard Bible Encyclopedia (1915)
pi’-e-ti: Only in 1Ti 5:4: "Let them learn first to show piety toward their own family," where "let them show piety" represents a single Greek verb (eusebeo), in its only other occurrence (Ac 17:23) being rendered "worship." In Elizabethan English "piety" (like the Latin pietas) could be used of devotion to one’s parents (as still in the phrase "filial piety"), as well as of devotion to God. Hence, there is no explicit statement here that filial devotion is one form of divine worship.