Psalm 85:8 I will hear what God the Lord will speak: for he will speak peace unto his people, and to his saints: but let them not turn again to folly.
When His resident Spirit says peace it stills our troubled hearts.
Psalm 25:16-18 Turn thee unto me, and have mercy upon me; for I am desolate and afflicted. The troubles of my heart are enlarged: O bring thou me out of my distresses. Look upon mine affliction and my pain; and forgive all my sins.
It is sin that afflicts the heart of a Christian. The loss of peace with God is the first signs of affliction. If we will be in tune with the peace of God, we can hear Him clearly. If we lose our peace we need to stop and look around to see at what point in our walk that we lost it. It will inevitably be sin which caused the loss. The loss of flow of peace is never caused by the Vine, the blockage will always be in the branches.
John 15:3-5 Now ye are clean through the word which I have spoken unto you. Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me. I am the vine, ye are the branches: He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing.
The first sign of a problem with the flow through the branches is loss of peace. Repentance and forgiveness restores the flow, but we have to search within ourselves for whatever sin has beset us.
The enemy will do his best to assault you on every level to steal your peace.