Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. (Philippians 4:6)
When I am anxious about getting old, I battle unbelief with the promise, “Even to your old age I am he, and to gray hairs I will carry you. I have made, and I will bear; I will carry and will save” (Isaiah 46:4).
When I am anxious about dying, I battle unbelief with the promise that “none of us lives to himself, and none of us dies to himself. For if we live, we live to the Lord, and if we die, we die to the Lord. So then, whether we live or whether we die, we are the Lord’s. For to this end Christ died and lived again, that he might be Lord both of the dead and of the living” (Romans 14:7–9).
When I am anxious that I may make shipwreck of faith and fall away from God, I battle unbelief with the promises, “He who began a good work in you will bring it to completion at the day of Jesus Christ” (Philippians 1:6); and, “He is able to save to the uttermost those who draw near to God through him, since he always lives to make intercession for them” (Hebrews 7:25).
Let us make war, not with other people, but with our own unbelief. It is the root of anxiety, which, in turn, is the root of so many other sins. So, let us turn on our windshield wipers and use the washer fluid, and keep our eyes fixed on the precious and very great promises of God.
Take up the Bible, ask the Holy Spirit for help, lay the promises up in your heart, and fight the good fight — to live by faith in future grace.