He will help you understand as you go...you will see it as you bear fruit. "I am the true vine and my Father is the vinedresser. Every branch in me that does not bear fruit, he takes away and every branch that does bear fruit, He prunes." John 15
Both the "taking away" and the "pruning" hurt. Your world will expand just past the pain, be assured. It is his promise. "By this, my Father is glorified, that you bear much fruit."