Don't & Do
So the words "Do not let your heart be troubled" is an amazing response...or maybe decision on Jesus' part to not let the circumstances divert his heart from where it needed to be. A "troubled heart" is, in many ways, my choice. I choose what to let in or not to my heart. I choose to allow stuff to trouble me or not. The second command is crucial for me: "Believe in God, believe in me."
Choosing to not do something rarely lasts for me unless I substitute doing something else, like believing in Jesus.