The mind is the battleground. What we believe and what we believe and act on or so determines most everything.
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.
Php 4:7 And the peace of God, which passeth all understanding, shall keep your hearts and minds through Christ Jesus.
Php 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.