What is the expiation for uttering and voicing doubt about God's knowledge and joy, and what is the expiation for this despair after injustice and dismissal from work?

Your utterance of words indicating discontent and impatience with Allah's decree is a grave evil. You must hasten to sincere repentance and accustom yourself to patience with Allah's divine decree and destiny. Indeed, Allah the Almighty is All-Wise, All-Knowing, and does not wrong people in the least. Whatever affliction befalls a person may be due to their sins, as Allah the Almighty said: "And whatever strikes you of disaster - it is because of what your hands have earned, and He pardons much." Therefore, repent to your Lord and increase your seeking of forgiveness, and fear Allah, for piety is a cause for bringing good and warding off evil. Allah the Almighty said: "And whoever fears Allah - He will make for him a way out And will provide for him from where he does not expect." Attach your heart to Allah and rely upon Him, for in His hand is all good: "And whoever relies upon Allah - then He is sufficient for him." And beware of discontent and despair, for every decree for the believer is good for him; if adversity befalls him and he is patient, it is good for him, and if ease befalls him and he is grateful, it is good for him.