As a Critical Care Registered Nurse I see a great deal of human suffering. Theodicy is the theological field of study that contemplates the existence of evil and suffering in a world created by a good God who is both omniscient and omnipotent. The Bibles answer to the problem of evil is the same throughout the entire Cannon of scripture; trust the Lord your God.
The books of Job and Ecclesiastes deal with this question on a personal level, but neither gives the full answer as to why there is human suffering. These two books acknowledge that evil and human suffering both exist. These two books also acknowledge God’s sovereignty, omniscience, kindness, righteousness and justice.
In the face of human suffering people have a tendency to doubt God. Human logic makes a God in our own image all the while forgetting that God is incomprehensible. The book of Job gives an answer for Job's suffering, but Job himself is not given an answer. We the readers get to look in on a scene in heaven that Job is not privy too. The preacher/teacher in Ecclesiastes says that all is vanity, that the good and the bad alike die. Neither Job nor Ecclesiastes gives the answer for human suffering, both point to the fact that human suffering does exist.
Therefore, when talking with someone who is suffering we should not deny that evil exists nor pretend that we have all the answers. What we do know is that God is sovereign and good, but let us never forget that God is incomprehensible. Therefore, let us not put him in a box. So when others are suffering acknowledge their suffering. Walk with them in their suffering, hold their hand and pray with them. Let them know that you do not have all the answers, but also let them know that God is good and God is Sovereign even in the face of their suffering and loss, therefore, “Trust in the Lord with all your heart and do not lean on your own understanding.” (Proverbs 3:5)