Our church believes there are way too many unsaved out there that belong to no church to worry about those that do. We do not accept new members from any other church unless they have tried to reconcile their differences with that church first.
When everyone claims to be some type of a Christian we will try to sort that out then.
Our church does the same thing. We try to reconcile folks who have left another church and don’t let them join until we’re satisfied that they have tried, or have good reasons to leave. Don’t want them bringing THEIR problems...smile.