I remember the first time I felt the loss of someone leaving our church. I was 14 or 15, and my dad was planting a church in Corpus Christi, Texas. My best friend and her family had been attending our tiny church, and they made the decision to leave for a church with a larger youth group, as they had a couple of teenaged daughters. And I get it. I understand why it happened. Having kids of my own, I want them to be a part of a church that feels like family— that they genuinely enjoy being a part of. But at the time, it hurt. It felt really sad.  But over the years that we've been in ministry, we have seen people leave churches for all kinds of reasons. Some of them were thoughtful and legitimate. Some of them were angry and uninformed. Some of them we never quite figured out why. Sometimes we have been the ones who left. We've wrestled with those decisions, too. Sometimes it was clear that God was moving us, and we were confident in our decision and other times, we felt like we...