The past several years I have been struggling with some friendships. I felt forgotten and used. It just didn't seem fair that I was being shut out and I just didn't know why. After mulling it over and over, I texted my sister-in-law about my struggles thinking she would probably just sympathize with me. Instead, she gave me the best advice on friendship that someone had ever given me.
"My mom once told me, "Some friends you have for a reason. Some friends you have for a season. Some friends you have for life. Don't try to push open a door that God has so clearly closed and locked. Simply thank Him that you were able to have that friendship and for the good that it was and move on.""
I read this text multiple times and let it sink in. My mother-in-law must have been a student of Aristotle or something, because he talked about something similar in Nicomachean Ethics.

Some friends were only meant to be in my life for a reason and/or a season. I believe it's because the Lord knew I needed them at that time. They may have stopped me from doing something I would regret, or maybe they helped me through a rough patch in my life. Maybe I was supposed to learn a life lesson from them. Maybe they were a guardian angel and I just didn't realize it at the time. I don't know. As time passed, those friends went separate ways. Although it stings and I still don't understand why, I trust that the Lord's will is best.

Through this struggle, I've come to be extremely thankful for the lifelong friends that God's put in my life. They are the ones that have kept in contact with me over the years despite distance and the constant demands of life. They are the ones I know I can call at a moments notice for prayer or advice. They are the ones who have encouraged me spiritually and have been uplifting in my life. They are the ones who I call my sisters in Christ, and to me, that's a most closer bond than just "friends."