Suffering may seem to be the biggest argument against the existence of a good and loving God. However this is a self-defeating question.
Without the existence of God there is no basis for saying anything is good or bad because this is a moral judgement. If God did not exist then there would be no logical basis for having moral absolutes. Without God, life is meaningless and suffering makes no sense.
If we look to the Bible for an explanation, we find that God is a good God who made everything perfect in the beginning but then, because of Adam and Eve's rebellion, death and suffering came into the world.
Suffering is a reality in our lives because of sin and can easily be likened to physical pain. Imagine you have your hand on a hot plate or you have fallen over and fractured your wrist. Without suffering the painful sensation that follows, perhaps you would not even realize the need to move your hand away from the hot plate or bandage your wrist.
Suffering can remind us that we do not live in a perfect world and that we ourselves are not perfect but sinful. It points us to Jesus, the One who comforts us in the present and is able to save us from future suffering that comes from eternal separation from God in hell.
For now, we can find comfort from Romans 8:18: "What we suffer now is nothing compared to the glory God will reveal to us later."