Godliness

The quality of being pious, devout, or reverent; behaving in a way that shows respect for God or religious principles.

'God' is from Old English 'god' (deity), and '-liness' comes from the Old English suffix '-lice' meaning 'like' or 'in the manner of.' So 'godliness' literally means 'god-like' behavior, eventually settling to mean religious devotion.