John 14:27

Peace that doesn't depend on circumstances going well — His peace, given, not earned. — John 14:27

John 14 is in the Gospel of John, New Testament — part of Jesus's farewell talk to His disciples the night before the cross. He knows what's coming and that they'll be shaken, so He promises them His peace and the Holy Spirit. This peace isn't the world's kind — it doesn't depend on circumstances going well.

'Let not your heart be troubled' is a command, not a suggestion — peace here is something received from Him, not something you have to manufacture.