Ibn Al-Qayyim (may Allah have mercy upon him) said that the word sadness does not appear in the Qur’an except, in the form of forbidding it or form of negating it and the reason for this because there is no benefit for having sadness in the heart. The most beloved thing to shaytaan is to make the believing slave sad by taking him off track. The Prophet Muhammad (peace & blessings be upon him) sought refuge in Allah from sadness.
Ibn Al-Qayyim (may Allah be have mercy upon him) said, sadness weakens the heart and diminishes determination and wanting to go forward. And there is nothing more beloved to the shaytaan than the sadness of a believer. For this reason, be happy, optimistic and think good about Allah. Have trust in what Allah is able to do and depend on him. You will find happiness and pleasure in all situations. Ibn Al-Qayyim (may Allah have mercy upon him) also said, don’t ruin your happiness with worry and don’t ruin your mind with pessimism. Don’t ruin your success with deception and don’t ruin the optimism of others by destroying it. Don’t ruin your day by looking back at yesterday.
If you think about your situation, you’ll find that Allah has given you things without asking, so have trust in Allah that he doesn’t prevent anything you want except there is goodness for you. You could be sleeping and the doors of the heavens are being opened with du’aas (supplications) being made on your behalf, subhana’Allah, perhaps from someone poor whom you’ve helped or someone sad whom you brought joy or someone passing by and you smiled at them or someone in distress and you removed it, so don’t ever underestimate any good deeds.
One of the righteous predecessors said, I make du’aa to Allah for something I want and if He gives it to me, then I am happy once and if he doesn’t, then I am happy ten times because the first was my choice and the second was Allah’s choice. As-Sadee (may Allah have mercy upon him) said, life is short, so don’t shorten it with worries, grief and sadness, so be the owner of a heart that breathes happiness and satisfaction.