Fault-Finding Christians

There is no doubt that we saw some of the best of many Christians and pastors after Charlie Kirk's assassination, at his memorial service, and in their sermons, podcasts, and posts afterwards. But sadly, we also saw some of the worst of some Christians and pastors fully on display. Even within the Reformed camp, there were those who criticized, nit-picked and found fault with other Christians and even other Reformed Pastors. What makes these "theologically superior" Christians so quick to attack a brother or sister who may not be as far along in their theology, but fully understand the true Gospel and are on the front lines preaching it?