Peace which passes understanding is the peace that Christ left with us. It is not circumstantial.
Jesus was relying on God's plan in the Gospels and He had this peace.
"Peace I leave with you; my peace I give to you. Not as the world gives do I give to you. Let not your hearts be troubled, neither let them be afraid." - John 14:27 ESV
Now Christ is seated in Heaven and the Holy Spirit is revealing Him in all His seated glory. Christ's position becomes our experience.
"And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus. Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things." - Philippians 4:7-8 ESV
Peace is what guards our hearts. The settled reality that our Saviour finished the work of salvation is intellectually true but knowledge is not enough. Knowledge would just be one factor to weigh in with many other considerations. Peace must 'go beyond' knowledge. It must go before us like the Ark went before the children of Israel.
Peace makes my mind safe enough to think pure excellent thoughts.
"If I ascend to heaven, you are there! If I make my bed in Sheol, you are there! If I take the wings of the morning and dwell in the uttermost parts of the sea, even there your hand shall lead me, and your right hand shall hold me." - Psalms 139:8-10 ESV
"But he, full of the Holy Spirit, gazed into heaven and saw the glory of God, and Jesus standing at the right hand of God." - Acts 7:55 ESV
Jesus stands to greet Stephen when he is martyred but He is sitting as we seek Him and stays seated when we make our bed in destruction. We find Him only in the finished work. That is the choice we have. God in His mercy may meet us many places but if we are looking that is where we find Him. He is presently seated in finished work victory. Interceding actively at rest in the position of highest honor to the right of His Father.
We can quiet ourselves because we must to have clarity but quiet is not peace. We need the peace that guards our hearts and minds. The inner quiet of a listening mind that seeks a seated Saviour.
Our wisdom starts from Love, Joy and Peace and continues from that place.
"But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law." - Galatians 5:22-23 ESV
"But the wisdom from above is first pure, then peaceable, gentle, open to reason, full of mercy and good fruits, impartial and sincere. And a harvest of righteousness is sown in peace by those who make peace." - James 3:17-18 ESV
If we find the throne of Grace we will have the resources to be peacemakers.