“Why do I carry on this business, or why am I engaged in this trade or profession? In most instances the answer would be, “I am engaged in my earthly calling so that I may support myself and my family.” Here is the chief error that causes almost all the other errors by children of God concerning their calling. To be engaged in a business merely to obtain the necessities of life for ourselves and family is not scriptural. We should work because it is the Lord’s will concerning us. “Let him labour, working with his hands the thing which is good, that he may have to give to him that needeth.” (Ephesians 4:28)
The Lord generally meets our needs through our jobs. But that is not the reason why we should work. If providing the necessities of life depended on our ability to work, we could never have freedom from anxiety. We would always have to say to ourselves, “What will I do when I am too old to work, or if I am sick?” But if we are engaged in our earthly calling because it is the will of the Lord for us, He is sure to provide for us because we labor in obedience to Him.”
http://www.worldwidetentmakers.com/education/reference-center/218-george-mueller-on-work
