This is what the Sovereign LORD, the Holy One of Israel, says: “In repentance and rest is your salvation, in quietness and trust is your strength, but you would have none of it. Isaiah 30:15 NIV
The only way we can have peace of mind is by eliminating anything that stands between us and God. How do we eliminate those things that stand in the way? By repenting and submitting to God. This can be difficult. God is willing to help – just ask Him! You will find rest in Him.