So many people, including Christians, are worn down by the world. They're tired. They have no peace. Their inner man is weary and it can find no rest, but only turmoil and strife. In Christ, we can obtain inner peace, but it requires that we dedicate our lives to righteousness; choosing a little righteousness and a little evil will never give us the fruit of peace we desire. Hebrews 12:11 says,
"All discipline for the moment seems not to be joyful, but sorrowful; Later on, however, it produces a harvest of righteousness and peace for those who have been trained by it."
If you lack inner peace, there is a solution, and it is choosing righteous behavior. Isaiah noted, "The fruit of that righteousness will be peace; its effect will be quietness and confidence forever." (32:17) Don't try to find peace through worldly activities, "for the kingdom of God is not eating and drinking, but righteousness and peace and joy in the Holy Spirit." (Rom 14:17)