The Lord Jesus guaranteed to grant us His indescribable peace in this magnificent verse. He is the only true source of peace because He is the eternal God of peace, and true peace comes from Him, not from the world. In the world, there is no way to achieve genuine or enduring peace. However impossible our external circumstances may appear to be, we can experience genuine peace from our wonderful Lord Jesus, and we need not worry or be fearful.
We were never guaranteed by the Lord that we wouldn't run into obstacles in life. He made it clear that we would experience suffering in the real world. We still reside in this world of misery and anguish even though we have been saved. However, the consolation we receive from the Lord Jesus' words, which reassure us that we can have peace even in the midst of our difficulties, is comforting.
These passages demonstrate that, regardless of our external circumstances, finding true inner peace requires that we look to the Lord Jesus, the source of peace. He will give us peace beyond understanding.

Dear Heavenly Father, at this moment, I choose not to give an audience to my fears or circumstances, no matter how dismal they may appear. You have freely offered me Your peace, and I have decided to accept it. Please take my worries, burdens, anxiety, and fears. Guard my heart and mind from all distractions, and help me live my life as You intended. I thank You for this peace. 
In Jesus's name I pray. Amen.