Read Joshua 1:1-5.

"Moses my servant is dead; now therefore arise, go over this Jordan, thou, and all this people,

unto the land which I do give to them, even to the children of Israel" (v. 2).

Today people seek inner peace through various means: self-actualization, positive thinking exercises, transcendental meditation, the practice of non-attachment, finding an inner light, chakras (spiritual powerpoint), seeking a spiritual guide, and using crystals, herbs, and so forth. The problem for those using these methods is that the result is never completely satisfying and quickly disappears. Besides these, Satan has many other options for those foolish enough to use them.
The Word of God, however, has a calming effect on troubled souls who look to God for peace of heart and mind. Jesus said, “Let not your heart be troubled.” This suggests that we have control over whether our heart is troubled or not. Jesus is telling us not to allow it to become troubled.
The question we face then is, “How do I exercise control over my spirit, so it is not troubled?" A foundational truth that must be accepted for this to be possible is understanding that peace is not the absence of trouble. True inner peace is only found in the presence of God. Peace comes from knowing that circumstances are temporary and that God is eternal. Peace comes from exercising faith in the character of the eternal God and His Word. Therefore we choose peace rather than fear or worry. In faith, we lean upon God and His promises instead of leaning on our own ingenuity. (Gayle Woods)

True inner peace is only found in the presence of God.