Born Again and have had their sins forgiven.
The one's who have a personal relationship with Jesus Christ.
And those very same people exist in every Protestant denomination and in the Catholic Church, etc.
Just too darn simple, isn't it? Institutions created by us humans complicate things. E.G., by the time St. Francis of Assisi died, the Franciscans and spin-off orders were among the largest real estate holders in Italy! Luther prayed the Rosary. Calvin and Zwingli read St. Augustine.
Newsflash! When ISIS , the Muslim Brotherhood, and the Taliban crucify, or behead a Christian, whether he's a follower of the Missouri Synod, the SBC, a Copt, or a Syrian Uniate Catholic really doesn't seem to matter to these Friends of Barack. Perhaps it ought not to matter too much to us.