"The peace of Christ must control your hearts - a peace into which you were called in one body" (Col 3:15, CEB) "Peacemakers who sow in peace reap a harvest of righteousness" (James 3:18, NIV) Perhaps, one of the greatest blessings that any person can have is to be at peace with themselves, to have the peace of mind that comes from a clear conscience, to be able to look at the mirror and be at peace with the person staring back at you; to be able to retire at night and sleep like a baby; to be able to enjoy your own company. There is nothing as refreshing as a heart at peace with itself. It heals quicker than the best medicine; it tastes better than the tastiest food and it enriches more than the wealthiest bank. Invest in your own peace of mind, and you will never go bankrupt. The Bible says peace must rule in your heart. It's not a suggestion. It is a commandment. Question is how do we achieve this peace.
I think it was Blaise Pascal who said that all of man’s miseries come from him not being able to sit still in a quiet room alone. If you give a dog a bone to chew on and a warm fireplace to curl up beside, it’ll be perfectly content. If you give a cat a scratching post and a sunny windowsill, it’ll be perfectly at peace. But if you give a man everything he could ever want, he will eventually grow restless. This is because the Adamic nature of sin has brought a curse of distress on man. Man is unable to be at peace with himself because of the great contention between good and evil that is going on within him. No man can be at peace with himself until he resolves that contention.
The conscience and the nature of God in us is always pushing us to be good and to do good. But the sinful nature and the temptations of the evil one is pulling us to the opposite direction. The more we listen to the sinful nature and deal unfairly with others, the more we are at war with ourselves. The funny thing is that our self peace comes not from how we treat ourselves but from how we treat others. If you want to be at peace with yourself, learn to treat others well. That is why Jesus said:
"Therefore, you should treat people in the same way that you want people to treat you;" (Matt 7:12, CEB)