Because it helps us grow in holiness, and because God uses suffering to show us where we need to change, suffering allows us to draw closer to God, it humbles us and helps us to trust God more and to lean on him. Suffering may builds empathy and compassion inside us if we choose to. 

Suffering can help us become more like Christ, to take up our cross and follow him, not in the sense of torture or martyrdom but instead to live a life of love and self denial. When we suffer we can understand Christ's suffering and the price He paid to save us from our sin.  

We come to understand him as God in the flesh who suffered the same or more than we have but still loved us and sacrificed for us. We come to understand God's mercy and love on a deeper level because of the suffering.

When we suffer, it might be because we have lost the true path of God. The suffering can be a correction. A way to guide us back to God's path of holiness and love. In this life we may get the reward of a better character, holiness and intimacy with God, and in God we have an eternity of bliss free from this life's trials.

We experience suffering because this fallen world causes pain and suffering.  We experience pain and suffering because sin entered the world as a consequence of mankind choosing their own way over God's.  

The first sin caused a rift between us and God through disobeying God.  This choice also entered sin and evil into the world with the effects of the fall being the suffering that still exists to this day. Jesus came into the world and suffered in our place and made a way for us to go to heaven and be with God for all eternity in peace without suffering.

Our suffering can help us understand God, what He has been through for us, and how much He loves us. God wants to help ease our suffering and bring us closer to Him. 

Our suffering is never a waste or something that has no purpose.  As God tells us, it may be that we need to go through hard times in order to enter a season where we can accomplish greater things.  

 For instance, God can work so much good through the lives of people who have been faced with tremendous suffering or great loss. The suffering of those who have been victims of war, poverty, or tragedy provides a deep sense of compassion and empathy that leads to many of the world’s most selfless and charitable acts.  

By surviving a crisis and recovering from trauma, many people also find the strength to lead positive changes in their community and in the world at large.  These survivors often have compassion for others and can be very understanding when they encounter challenges or suffering in others.

Suffering isn't pleasant, it is hard. God allows us to suffer because it may lead to greater things. It may lead to holiness, greater love, and ultimately it leads to the greatest gift of all. An eternity in heaven, free from the pains of this world, united with God for all eternity.