Because we're fallen people who are looking for satisfaction through our own efforts, we each carry the infection of demandingness within us... 

We were designed to love and when we do, something good develops inside. We feel clean, rich, and whole. Even better, we become less concerned with how we feel and more concerned with the lives of others. But when a commitment to self-protection governs what we say, how we say it, and to whom, then a nagging discomfort creeps through our soul that demands to be soothed. We then find ourselves becoming angry when people fail to care about us as they should... a demanding spirit violates the love we call for, but that spirit, which others sense in the way we relate to them, often remains unaddressed. 

Bitterness develops when people don't respond to our demands. some folks get frightened by their own anger ("if others saw my anger, they'd reject me even more") and hide it beneath depression or nervousness or obsessive thoughts about harming someone. Others express their anger more directly through outright ugliness:  They may become overly critical, blatantly rebellious, or just obnoxiously sullen with those who've let them down...

"Go and say to this people: 'When you hear what I say, you will not understand. When you see what I do, you will not comprehend. For the hearts of these people are hardened, and their ears cannot hear, and they have closed their eyes—so their eyes cannot see, and their ears cannot hear, and their hearts cannot understand, and they cannot turn to me and let me heal them.'"‬‬ - Acts 28:26-27 NLT

An honest look will in every case eventually expose something terribly ugly—demandingness. We are a demanding people... We demand that no one hurt us again the way we were hurt before; we demand that legitimate pleasures , long denied, be ours to enjoy... When we assume responsibility for what we desperately require but cannot control, we irrationally demand that our efforts succeed. Wedged tightly in our thirsty soul is the ugly disease of the demanding spirit. 

Change from the inside requires that we take a disturbing look at the ugly parts of our soul; that we face our problem of demandingness and do something about it.  The sin of demandingness must be identified, recognized in all its ugliness, and abandoned through repentance.