In fact, that tendency is the very thing that is so poisonous about all forms of pietism and theological liberalism. Whenever you elevate good deeds over sound doctrine and true worship, you ruin the works too. Doing good works for the works' sake has a tendency to exalt self and depreciate the work of Christ. Good deeds, human charity, and acts of kindness are crucial expressions of real faith, but they must flow from a true reliance on God's redemption and His righteousness. After all, our own good works can never be a means of earning God's favor; that's why in Scripture the focus of faith is always on what God has done for us and never on what we do for Him (Rom 10:2-4). Observe any form of religion where good works are ranked as more important than authentic faith or sound doctrine, and you'll discover a system that denigrates Christ while unduly magnifying self.
from Twelve Extraordinary Women by John MacArthur.
Does he thank the servant because he did the things that were commanded? Even so you also, when you shall have done all the things that are commanded you, say, We are unprofitable servants; we have done that which it was our duty to do. (Luke 17:9-10).