But St. Paul goes on: “Be careful for nothing,” he says. In other words, "Don’t be anxious about anything." Of course, it’s right to think about the future and to do everything that we can to provide for it, but if we’ve honestly done all He has told us to do, then we should be at peace in the assurance that He won’t allow us to lack anything that we truly need.
And then St. Paul tells us that if we want freedom from anxiety and a quiet confidence in God then we must take everything to God in prayer. Obviously we can’t be always on our knees in prayer – but we can live a life of constant prayerfulness, which means that wherever we are, whomever we’re with, whatever we’re doing, we can remember that we’re in God’s presence, so that all of life becomes part of our prayer.
And we’re reminded of another thing: we must live in a spirit of thankfulness. There can be no peace or joy in an unthankful heart.
So if we want the peace of God, then we simply need to do what God has told us to do in the way of preparation, and then trust Him as our Father, telling Him everything in our hearts, relying on His care, and in that way we’ll find freedom from the anxieties of this world, and we’ll have that “peace which passes all understanding…”