I recall answering a question in a graduate class that asked if all pain was bad pain? My initial response to this question was yes. Focusing on the physical feeling of pain, I wrote that some pain may be less severe, but all pain is bad due to experiencing some form of discomfort. Reading the responses of my classmates gave me a different insight on pain. I learned that one purpose of pain is to tell us that something may be wrong and needs to be corrected. If we didn't experience pain, we wouldn't feel the need to fix anything in our lives. This is why pain is necessary. All pain causes discomfort but it's needed to make us aware of the changes that we need to make. The pain that you are experiencing could be placing the spotlight on something that needs to be changed. The pain that comes from rejection could be God telling us that we need to eliminate bad habits or strengthen our faith before he can bless us with what we're seeking. We can't accomplish positive things with negative thoughts or receive Heavyweight Blessings with a Lightweight Mindset. I use these illustrations to demonstrate that old ways can't be brought into new situations.
One purpose of pain is to provoke a response from us. Think about the last time you had a headache or hit your toe off the side of the bed. I'm sure it provoked a response to either massage the sore area, or to take medication to alleviate the pain. God uses pain to accomplish the same thing, using it to provoke a response to his calling or the areas of our life that need to be improved. This is necessary before he can elevate us to the next level. He wants to see us make an effort to enhance our lives, and pain brings attention to what need to be altered. One definition of the word altered is making structural changes. In order to reach the level that God wants to elevate us to, we may need to modify the way our lives are structured. If we never experienced pain in our lives, how often would we strive for improvement? Pain isn't ideal, but it's often the water to our seed of growth.