The question implies the existence of a Being (God) able to eliminate pain, if only He were willing. Surely He knows we are often quite miserable. We human beings are so constructed that pain is sometimes unavoidable. Our nerve endings howl in protest when our bodies are injured. And we are not the only creatures who experience pain. Animals suffer too. But our pain may be intensified by our ability to anticipate it and to question it. If God can stop it, why doesn’t He?
The answer may be, in part, that God does stop it many times. Read the life of Jesus as recorded in the New Testament. On some occasions, He nearly exhausted Himself healing sick people—as God the Father’s surrogate. But He did not treat every sick person in the land. He could not have done it without compromising His mission, which was to preach and teach the Word of God and, when the time came, to die for our sins. Time and space made it practically impossible for Him to wipe out sickness and pain during His time on earth.
God in Heaven is not hindered by the limitations imposed on Jesus by the incarnation. He doesn’t grow weary or get thirsty or have to ask, “Who touched me?” Yet even God in Heaven cannot do everything that we mortals might ask Him to do, including the complete elimination of pain and suffering. It is not strictly correct to say that God can do anything. He cannot deny Himself (2 Tim. 2:13 nasb), He cannot lie (Titus 1:2), and He cannot be tempted by evil (James 1:13). These and similar statements about God imply that His activity in the universe is constrained by the reality of His character.
Another reality is the fall, meaning that Adam’s and Eve’s initial transgression resulted in a state of alienation from God. Humanity’s natural disposition has been bondage to sin ever since. Yet we retain elements of the image of God, including freedom to make choices. With that freedom, we can and often do choose to sin, and sin brings sad consequences, including pain and suffering. God acts in a broken universe where He cannot bless His creatures to the extent that He would if not for their abuse of freedom.
Even so, “The Lord is good to all; he has compassion on all he has made” (Ps. 145:9). Read Psalm 103 for insights into the ways of God that most directly affect us. From many other texts, see how He has planned a pain-free eternity for His redeemed people. In due time, He will make everything conform to His design.