Human lives are by their very nature, fragile and fleeting. We allow ourselves to be consumed by the minutia of life and lose track of just how nothing is promised to us, not tomorrow or even today. I think this is why we are to trust in the Lord, turn our problems over to him, and focus on Love.
The reality is that there are some problems that we can not fix or possibly even cope with by ourselves. All we can do on our own is relentlessly obsess over them and compound the problems by feeding our anxieties and fears. In turning our problems over to the Lord, we talk about them, we name them, we unburden ourselves, and we are no longer alone.
When we focus on Love, loving our neighbors and our enemies, we build relationships. We begin to focus ourselves on the needs and well being of others, putting them before ourselves. In doing so our own worries fall away, especially if we have already turned our worries over to the Lord.