My child, be cautious both when you are happy and when you are sad.

My child, be cautious both when you are happy and when you are sad. When you are happy, you should not lose your self-restraint due to liveliness and laughter, nor should you be so downcast when you are sad that it becomes noticeable. This happens because Satan attacks us with thoughts like arrows, but he cannot conquer us if our heart is not receptive to it. However, he is very skilled, and once he shoots an arrow, that is, when he attacks us with bad thoughts, he observes our face and every movement of our body, and based on that, he assesses how well the arrow hit our heart. Therefore, when you are happy, you should conceal it within yourself, so that he cannot expose your negligence and rob you with some temptation.

Furthermore, when you are sad, do not show it to him because, having discerned the cause of your sadness, he will increase your pain. If you manage to be balanced both when you are happy and when you are sad, the devil will not be sure what is happening within you, so he will not know how to fight with you.

Elder Ephraim of Philotheou and Arizona