Philippians 4:8 "Finally brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things."
Worry is something that we all have battled at one time or another. Worry robs us of our joy. Worry only changes one thing...the color of our hair!! (And boy is mine changing!!) But worry is sin!! Worrying shows lack of faith.
Someone said to me once, "There are things you should never worry about...the things you CAN change and the things you CANNOT change."
Worry is the result of looking at circumstances, people and God in the wrong way. Isaiah 26:3 "Thou wilt keep him in perfect peace, whose mind is stayed on thee: because he trusteth in thee." Wrong thinking leads to wrong feelings and wrong feelings lead to wrong actions. That is why we must bring as it says in II Corinthians 10:5 "...into captivity every thought to the obedience of Christ."
Paul gave us a THOUGHT TEST. He tells us in Philippians 4:8 "...think on these things." Ask the following questions about your thoughts and the things you do. TRUE...is it true to the standard of God's Word? Tell the truth...don't believe lies. HONEST...is i honorable and trustworthy? JUST...is it upright? Is it based on principle? PURE...is it clean of carnality? Is it chaste and pure? LOVELY...is this something beautiful in God's eyes? Does it inspire me to love others as God does? GOOD REPORT...is it of good reputation? Is it worth talking about? VIRTUE...does it motivate me to do better? Does it build my Christian character? PRAISE...is it worthy of praise? Can I recommend this to others?
If we think on these things then we have nothing to be worrying about. When we hold "into captivity every thought to the obedience of Christ" then there will be peace and not worry.
Hope this helps you as it helped me.