I think the go to question we have when we are going through any kind of trial is "why?" Being someone who does not believe that "everything happens for a reason", this question doesn't really make a lot of sense. And yet, I still find myself coming back to it in regards to infertility.
"Is this because I don't trust God enough?"
"Is this because I am too controlling?"
"Is this because of that one time when I was 12 years old, and someone was sharing in church about the pain of infertility, and I thought she was being overly dramatic and should just adopt?"
But I love this passage. I think it answers beautifully why God allows us to suffer.
"Store up comfort. This was the prophet Isaiah's mission. The world is full of hurting and comfortless hearts. But before you will be competent for this lofty ministry, you must be trained. And your training is extremely costly, for to make it complete, you too must endure the same afflictions that are wringing countless hearts of tears and blood. Consequently, your own life becomes the hospital ward where you are taught the divine art of comfort. You will be wounded so that in the binding up of your wounds by the Great Physician, you may learn how to render first aid to the wounded everywhere. Do you wonder why you are having to experience some great sorrow? Over the next ten years you will find many others afflicted in the same way. You will tell them how you suffered and were comforted. As the story unfolds, God will apply the anesthetic He once used on you to them. Then in the eager look followed by the gleam of hope that chases the shadow of despair from the soul, you will know why you were afflicted. And you will bless God for the discipline that filled your life with such a treasure of experience and helpfulness." (from Streams in the Desert)
We're still very much in the middle of infertility, but we're a little bit further along than we were, and we don't feel the despair we once did. We are already seeing in small ways how God is using this trial in our lives to comfort others. He is bringing people into our lives who have been afflicted with infertility, and I imagine there will be many more over the years. Not that we have anything particularly comforting to say, but sometimes (especially with infertility), it's just nice to know that there are others going through it.
So yes, this is costly training, and I'd much rather not have to train (I hate any kind of training), but I hope that it will allow us to help bind the wounds of others that are being bound for us right now.