"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" (Colossians 3:23-24).
Not only do we need to abstain from being lazy, but we should work with all of our heart. When God gives us a purpose, He gives us passion.
Pray that you are consumed with fire for what God has called you to. This does not necessarily mean that you won't have rough days here and there. Those days come no matter what you do. However, it does give us the strength to fight through those difficult days when we feel like quitting. When we are burdened for a cause, we are moved to action. When we are moved to action, we are hungry for accomplishment. When we are hungry for accomplishment, we would do well remembering why we're working.
Though sometimes it is difficult to remember, keep in mind today that "it is the Lord Christ you are serving."