Many people who work very hard to earn money is driven by either insecurity or greed.

If we have experienced financial difficulty or know someone who have, then it is natural for us to want to avoid that. While for some people, they chase wealth because they like all the trappings of it and they are greedy for more and more.

Not everyone is like that, but many are.

"
Beware! Guard against every kind of greed. Life is not measured by how much you own.
...
Look at the ravens. They don’t plant or harvest or store food in barns, for God feeds them. And you are far more valuable to him than any birds! Can all your worries add a single moment to your life?
"

(Luke 12.15, 24-25 NLT)

So, why work hard?

Work willingly at whatever you do, as though you were working for the Lord rather than for people. Colossians 3.23 NLT