Php 4:6 Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God. And the peace of God, which passeth all understanding, shall keep your hearts and minds through Christ Jesus.
The “Be careful for nothing” implies a lack of anxiety over worldly affairs. Not that we won’t do things to take care of ourselves or our loved ones, but that we shouldn’t be worried about it. How can one worry when eternity with God awaits us?
Mat 6:25-34 Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment?
Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Are ye not much better than they? Which of you by taking thought can add one cubit unto his stature? And why take ye thought for raiment? Consider the lilies of the field, how they grow; they toil not, neither do they spin: And yet I say unto you, That even Solomon in all his glory was not arrayed like one of these.
Wherefore, if God so clothe the grass of the field, which to day is, and to morrow is cast into the oven, shall he not much more clothe you, O ye of little faith?
Therefore take no thought, saying, What shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed? (For after all these things do the Gentiles seek:) for your heavenly Father knoweth that ye have need of all these things. But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you.
Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof.
Jesus points out that acting in that way is like the Gentiles, or those outside of Israel. Today, that would be the unbelievers. In other words, the unbelievers worry about what to wear and what to eat. We’re different because of where our hearts and hope should be, in God. Our trust is in God, so the worldly matters should not concern us.
What we own now, what we do now, what we suffer now, is all irrelevant compared to the everlasting glory of Heavan. Anxiety over such temporary problems is both useless and contrary to the trust we say we have in God to take care of us (in the eternal long term).
Back to Philippians, Paul says the alternative to worry is prayer. We’re not going to talk ourselves out of our worry. But God can fill us with such peace that we won’t suffer with it. Paul tells us to pray and to tell God about all of our concerns and requests and things we’re thankful for. God’s peace, which is WAY beyond our understanding, will keep us and guide us and hold us safely.