What you do reflects who you are; it's not who you are.
In a Washington Post article entitled, Are You A Work Martyr, Brigid Schulte notes 40% of Americans don't take all their vacation, leaving 430 million days of unused paid vacation a year.
Somewhere along the line we, Americans in particular, are seeing work as somehow validating our existence. What we do is informing who we are. Authors Staats and Geno write in a Harvard Business Review article, It's The Weekend! Why Are You Working!, many simply find joy in their work. Work can consume us; however, at the same time we enjoy it.
As Christians we can see that work was given us before sin entered into the world and was part of what God called good (Genesis 2). We must temper this with 2 other things God gave mankind in Genesis 2 - the Sabbath (rest) and Eve (family/community). Balance, as always, becomes key in the Christian worldview - especially regarding work.
Who are we then, if not what we create/do? We're created in the image of God (Genesis 2); known by God (John 10:3); pursued by God (Luke 19:10) and finally redeemed by God (Ephesians 2: 8-9). This is the foundation of our identity. By the grace of God we receive relationship with our creator - we don't achieve it; and here in we can rest. What you do is reflects who you are; it's not who you are. If your ability to work were taken away would you fall apart? Is there more to you than the work you do?