The peace of justification is not only external. The deepest longings for inward peace are also met in Christ. It was St. Augustine who once prayed, “Thou hast made us for Thyself, and our heart is restless, until it finds its rest in Thee.” We all know what it means to be stricken with inner restlessness. We know the gnawing feelings of emptiness and guilt that come from estrangement from God. Once our peace is established, that awful emptiness filled, and our hearts may be still.
– R.C. Sproul, The Holiness of God, Tyndale House Publishers, Carol Stream, Ill., Copyright 1985, Kindle Edition