What is the meaning of [Cleanliness is next to godliness]

Cleanliness can be defined as ‘diligence in keeping clean in person and
dress’; and ‘next to’ means ‘second only to’. Francis Bacon wrote in his
_Advancement of Learning_ : ‘Cleanliness of the body was ever deemed to
proceed from a due reverence to God.’ The axiom certainly dates back to very
ancient times.