Quotes from the Saints
The Four Hundred Chapters on Love:
135. There are many things done by men which are noble in themselves but still because of some reason are not noble. For example, fasts and vigils, prayer and psalmody, almsgiving and hospitality are noble in themselves, but when they are done out of vainglory they are no longer noble.
136. God searches the intention of everything that we do, whether we do it for him or for any other motive.
137. When you hear the Scripture saying, "You will render to each one according to his works," know that God will reward good works but not those done apart from a right intention even if they appear good, but precisely those done with a right intention. For God's judgment looks not on what is done but to the intention behind it.
St. Maximus the Confessor