Why do people die? Death teaches us some important lessons. Our death teaches us that we do not own our lives. We do not own our lives because the owner can ask for it at any time he wants. He can take it at any time he desires. If we were to have power over our lives, we would have to dictate our long we would have lived. But as it is, God owns life. He gives us for a season and he can take it at any time he wishes.
When we know that the life is not ours, we should obey the instructions of the one who gives us the life. We should accept his teachings. We should follow his commandments. Living in this world without listening to God's commandments is foolishness.