Is saying, "We will all die," in response to "Are you saddened by your deceased grandmother?" considered ungratefulness and indifference towards death, or is it submission to God's inevitable decree, knowing that I seek forgiveness for her and pray for her mercy?

Death is the destiny of every soul, and a Muslim must be patient in the face of calamities and pray for their deceased relative for mercy and forgiveness. Grief does not contradict patience, for the Prophet, peace and blessings be upon him, grieved for his uncle Hamza and his son Ibrahim, and he said: "Indeed, the eye sheds tears, and the heart grieves, but we do not say except that which pleases our Lord. And indeed, we are saddened by your departure, O Ibrahim."