devotion vs theology

devotion

noun
  • Religious veneration, zeal, or piety. 

  • The act or state of devoting or being devoted. 

  • Feeling of strong or fervent affection; dedication 

  • A prayer (often found in the plural) 

theology

noun
  • A particular belief within a religion. 

  • Synonym of religious studies 

  • Subjective marginal details. 

  • An organized method of interpreting spiritual works and beliefs into practical form. 

  • The study of God, a god, or gods; and of the truthfulness of religion in general. 

How often have the words devotion and theology occurred in a corpus of books? (source: Google Ngram Viewer )