The whole of practical piety (1 Timothy 4:8; 2Pet 1:6). "It supposes knowledge, veneration, affection, dependence, submission, gratitude, and obedience." In 1 Timothy 3:16 it denotes the substance of revealed religion.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Godliness'". "Easton's Bible Dictionary".