Grace is understanding that everything we have is on loan from God. It’s the opposite of entitlement. Job survived his grief and suffering because he held onto a robust theology of grace. He knew that he was not entitled to anything he had. Everything he had was on loan from God. He “got” grace. He “got it”. He didn’t live with a sense of entitlement – “I deserve better than this, God.”
Job did not locate his identity in what he had. If the foundation of your happiness is in what you had (relationships, name, money, etc.), then suffering will be pulling you away from those foundations. That will make you mad, bitter, and sad and so on.
But, if like Job, you build your life on God so that the ultimate love is God’s love, then suffering actually drives you deeper into your source of joy (God). Suffering exposes what you are building your life on.