Definitions of devotion:

• noun:   (usually plural) religious observance or prayers (usually spoken silently)

  Example: "He returned to his devotions"

• noun:   commitment to some purpose

  Example: "The devotion of his time and wealth to science"

• noun:   feelings of ardent love

  Example: "Their devotion to each other was beautiful"

• noun:   religious zeal; willingness to serve God