Nobody can really put a hand on why God allows suffering. Some say  that if God were to be good and loving, He would not allow suffering.  But we who are saved by His grace know that all things (including  suffering) work together for our good (Romans 8:28).

The truth is that God will never allow His children to go through  what He has not provided adequate grace for them to bear. He said to  Paul, “My grace is sufficient for you and my strength is made available  to perfect your imperfections” (2 Corinthians 12:9).

While we may not understand the purpose of suffering in its early  phase, one truth however is certain, we understand better by and by. God  loves His children and empathises with us in our sufferings. We can be  certain that if He allows it, it will turn out for our good.