Each person has to work according tot he will of God. When we understand this, we will never face any difficulty or problem in carrying out our day to day work.  On the other hand we will be filled with the joy of the Lord.  For this we have to keep two things in our mind. First accept that whatever work we do, we do it for the Lord. But in reality the contrary is happening; we all want to do our will not God's will.  The Word of God says "There is nothing I cannot do in the One who strengthens me" (Phil 4:13)

Without working hard we are not able to gain anything.  When the Lord is with us, we will be able to do everything. We read in (LK 18:27) that "He replied, things that are impossible by human resources are possible for God." for doing good less energy is consumed than energy used for doing bad. "May you be made strong with all the strength that comes from his glorious power and may you be prepared to endure everything with patience, while joyfully giving thanks to the Father, who has enabled you to share in the inheritance of the saints in the light" (Col.1:11-12).

In our day to day life for everything both good and bad alike, we have to exert energy i.e. work. For e.g. for eating, dressing up, for drinking etc. our energy is exerted.  After satisfying our basic necessities also, we continue to work for achieving out higher expectations.  We should not forget that "Unless the Lord builds the house, those who build it labour in vain" (Ps.127:1)