Is to think that one should be free from sadness a feeling of entitlement or its result, only a symptom of narcissism or disordered self-love? Is sadness an evil, not just a sensible reaction to some evil or to a privation/deprivation? (Let us focus exclusively on the privation of necessary goods, rather than what is superfluous. We would not feel sad if we did not attain something we desired that was not truly necessary for our well-being.) Did God desire for us to feel or experience sadness? In a creation rightly ordered, would there be sadness? Everyone would be acting virtuously, and there would be no physical evils. There is no feeling or experience of sadness in heaven. What of feeling sad because of social discord or enmity? Are friends luxuries rather than a good that is necessary to us and our flourishing?

Pravmir: What the Fathers of the Seventh Ecumenical Council Have Done For Our Salvation and Sanctification by Archimandrite John Krestiankin (+2006)