As nouns the difference between holiness and saintliness
is that holiness is (countable) used in connection with his]]'' or ''[[your|your to address to the pope while saintliness is the property of being saintly.
holiness
English
Alternative forms
* (all obsolete) holinesse, holyness, holynesse
Noun
(es)
The state or condition of being holy.
Synonyms
* (state or condition of being holy) sanctity
Derived terms
* His Holiness
* Their Holinesses
* Your Holiness
saintliness
English
Noun
The property of being saintly.