Everyone has been created with three God-given inner needs - the needs for love, for significance, and security. When one or more of these needs is no longer being met, we naturally feel a sense of loss.
Unmet need = Sense of loss = Feeling of grief
Throughput our lives we will incur numerous losses. Although we need to feel the pain of our losses, we do not need to be controlled by our losses.
Instead we must rely on God's promise that He will meet our deepest inner needs.
"My God will meet all your needs according to his glorious riches in Christ Jesus." Philippians 4:19