I suppose you are saying faith it till you make it, believing in Him already calming to the point that your mind and body follow? Well, I look forward to this kind of peace. Today I made a mistake at work and I have been stressing. Not sure how to not be, because I making mistakes isn't ok at work. I will have to move forward though becauae there is nothing i can do about it now, but give it to God.
I have this mindset to where im not committed to change things, im committed to changing me, my imaginations of them and my reactions, responses and treatments of them. When the truth of something is based on how you're treating it you can overlook the lies of its vain ignorant behaviors and rest in the peaceful truth of how you're treating it. You keep your attention on you because you have Christ/God the truth within you that makes you the truth, you don't need to be looking at anything else but what you're doing/treating and imagining things to be because you are that evidence of things unseen.
The body has no choice but to obey and respond to truth. I remember when my stomach was basically skrewed up to the point where i could barely drink and i couldn't eat at all. Every day for several days i would just sit at the kitchen table with an empty bowl and spoon and i would simulate eating for 20 minutes once in the morning and once in the evening. I honestly thought i was going to die and i was also fighting with thoughts about ending myself because starvation and dehydrating to death is ugly.
I figured if im going out might as well do it with Romans 12:2 and Hebrews 11:1 tatted on my chest lol. If faith is the substance of things hoped for the evidence of things not seen i was focused on making it seen by God because i was pretty much fed up and tired of asking Him over and over again to heal me only to have my hope deferred.
It's like i can't see what you're saying about me already being healed but ok, because this is about YOUR beliefs about me watch me simulate eating, maybe then you'll allow me to fill this bowl so i can eat for real. After a week and a half someone just randomly tells me "you should just eat what you want". I didn't even tell them about what i was going through so i knew that was a que from God through that person so it's like "ok then" and i started eating and ive been eating just fine ever since.
So in a way yes i am calm off of what Jesus did but at the same time im also calming and satisfied off of my own actions, responses and treatments of things.
As for your mistake at work, you made a mistake on the outside, take it with grace, you're allowed to make mistakes no sense in crucifying yourself. When i make mistakes i tell people straight up that im allowed to make mistakes sometimes and that im not going to crucify myself over it. I tell it to them because im basically saying that im not going to be bound to it because believe it or not there are some people out there who have the sole intent of getting people to internalize stuff like that. Also as you forgive yourself forgive others when they mess up it's liberating for both them and for you too.