Colossians 3:23-24 (NIV)
Whatever you do, work at it with all your heart, as working for the Lord, not for men, since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving.
This is an important principle. God gave Adam work to do in the Garden. Work has dignity because of this. After Adam sinned, God made him work by the sweat of his brow. Work is still dignified, just a lot harder. Now if we serve Christ, why should we work so hard for that mean boss we've got? Because that mean ole boss knows you serve Christ. He'd get the wrong idea about Christians if you were a slouch. By the way, work is a lot easier and you'll be encouraged to go the second mile when you realize you really work for the Lord! Everything that employer gives you is going to rust or turn to dust eventually anyway. What the Lord has waiting for you is infinitely better and knowing this, He has told you to work hard because of it.
Matthew 5:16 (NKJV)
Let your light so shine before men, that they may see your good works and glorify your Father in heaven.