Galatians 5:22-23 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, meekness, temperance: against such there is no law.
I think the best way to approach the issue of peace is in looking at the words of Jesus Himself.
John 14:27 Peace I leave with you, my peace I give unto you: not as the world giveth, give I unto you. Let not your heart be troubled, neither let it be afraid.
It is an issue of the heart. Being troubled speaks to being unsettled. This is caused by looking at the world from a worldly viewpoint. Every treaty ever made has been broken. The world changes all around us and we do not have control over events. Stable governments become unstable. Just rulers die. Borders are threatened. We see with less than 20/20 hindsight thinking that if we had made other choices, things would be different. Yes different, but with different comes a new set of circumstances and opportunities. Mankind is after all still mankind.
So how does the peace of Christ differ? What is the fruit of peace? As it is not of the world, then it differs mainly in He who makes the promise. He is God not man. He does not lie. His word is true and His assurance has the power of God to enforce His surety. With God’s peace we are settled, stable, and resting in His everlasting arms.
Deuteronomy 33:27 The eternal God is thy refuge, and underneath are the everlasting arms: and he shall thrust out the enemy from before thee; and shall say, Destroy them.
As to fear, He says let not your heart be afraid. Fear is greatest when we feel alone. In Hebrews 13:5 He said, I will never leave thee, nor forsake thee.
Deuteronomy 31:8 And the Lord, he it is that doth go before thee; he will be with thee, he will not fail thee, neither forsake thee: fear not, neither be dismayed.
Peace I leave you, MY peace, saith the Lord.