I agree with your comments, with the clarification that many who call themselves Christian, and think they're Christian, actually aren't (people who criticize bad Christians may actually be looking at false Christians). There are some bigger discussions of how mistaken can a person identifying themselves as Christian be in their doctrine and practice and still be reconciled with God, but there are lines that if crossed means one was never actually a Christian, or ceased to be a Christian. "Watch your life and doctrine closely. Persevere in them, because if you do, you will save both yourself and your hearers.", "“Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven. Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?’ Then I will tell them plainly, 'I never knew you. Away from me you evildoers!".