Have you ever heard the term don’t cry over spilled milk? That is an example of what this claim is talking about. It is basically useless to put stock and effort into being concerned in things that we cannot have control over. If we cannot change the outcome of events then it is only a waste of our time and energy in thinking about ways to change said thing. We can find things to be more productive to be useful with our time with. That is the thought process behind the claim.

Is it Biblical?

The best example Biblically about not putting effort into things you cannot control is David not crying over his dead son:

“David noticed that his attendants were whispering among themselves, and he realized the child was dead. “Is the child dead?” he asked. “Yes,” they replied, “he is dead.” Then David got up from the ground. After he had washed, put on lotions and changed his clothes, he went into the house of the Lord and worshiped. Then he went to his own house, and at his request they served him food, and he ate. His attendants asked him, “Why are you acting this way? While the child was alive, you fasted and wept, but now that the child is dead, you get up and eat!” He answered, “While the child was still alive, I fasted and wept. I thought, ‘Who knows? The Lord may be gracious to me and let the child live.’ But now that he is dead, why should I go on fasting? Can I bring him back again? I will go to him, but he will not return to me.”” – 2 Samuel 12:19-23 NIV

David says it well; while his son was sick, he fasted and wept because perhaps God would be gracious and let him him but now that he is dead he can’t do anything about it. David knows that there is no point in putting effort into trying to bring back his dead son because it’s pointless so instead he is moving on with his life. This is the type of mindset we should have.

I’d further like to add that the Bible tells us not to be anxious about anything as well:

““Therefore I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more than food, and the body more than clothes? Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they? Can any one of you by worrying add a single hour to your life? “And why do you worry about clothes? See how the flowers of the field grow. They do not labor or spin. Yet I tell you that not even Solomon in all his splendor was dressed like one of these. If that is how God clothes the grass of the field, which is here today and tomorrow is thrown into the fire, will he not much more clothe you—you of little faith? So do not worry, saying, ‘What shall we eat?’ or ‘What shall we drink?’ or ‘What shall we wear?’ For the pagans run after all these things, and your heavenly Father knows that you need them. But seek first his kingdom and his righteousness, and all these things will be given to you as well. Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.” – Matthew 6:25-34 NIV

God clearly tells us not to be overcome with worry since he cares for things far less valuable than us and that shows that he would definitely care for us. This passage also highlights that God provides all we need so worrying about our needs being met is useless and about the fulfillment of tomorrows worries as well. We need not be anxious about anything. Letting ourselves be anxiety ridden is a form of letting ourselves be controlled. Instead of being able to control the thing in the future or outside of your control you worry about it instead. One way to not put effort into things outside of your control is with worry.

So adding all of these things together. If we cannot change the outcome of something we shouldn’t put any effort into trying to changing it even more so we shouldn’t even worry about it. If you cannot change the outcome of something, then place it out of your concerns and do not worry about it.