11 Be glad in the Lord, and rejoice, O righteous, and shout for joy, all you upright in heart! ~ Psalms 32:11
Equilibrium is the state of balance or the adjustment of conflicting desires. In other words, when your inside does not match your outside, you have an imbalance in your equilibrium. Your body will then work to adjust the one with the other, and usually, the one with the strongest emotion, or the one you push the hardest, will be the dominant one.
For example. Suppose you are feeling good inside, but you pretend to be upset, and your face shows it; your words tell of it, and you act like you are upset. Soon your inside will begin to match your outside since it’s your dominant emotion, the one you are pushing the hardest, and you will begin to feel angry or upset, and you won’t even know why.
That is your equilibrium adjusting to balance the two; your inward and your outward. That is why God commanded them to be glad, or in other words, to begin celebrating with song and with clapping of hands. With shouts of elation and with whatever other outward expression of celebratory joy there maybe. Even before they begin to feel it inwardly.
Express it outwardly, and in due time, the inward will match the outward, and you will begin feeling the joy of the LORD, and the heart will rejoice and be thankful and grateful for all the LORD has done because His goodness is forever.
Peace. Love. Go Forth and Celebrate The Goodness of The LORD.