When the Lord discusses His church, he often is not referring to the ecclesiastical organization but a group of followers—those who follow him and repent of their sins. This broad definition is given in the D&C, Behold, this is my doctrine—whosoever repenteth and cometh unto me, the same is my church (DC 10:67). This seems to be one of the meanings in verse 22 because the Lord had spoken of those that will hear my voice (v. 21) and those who are baptized unto repentance. Based on the D&C definition, it is possible to be a Mormon but not a member of His church. The unrepentant and self-righteous Mormon is like the children of Israel who thought that salvation came by virtue of their descent through Abraham, saying, Abraham is our father. Jesus saith unto them, If ye were Abraham’s children, ye would do the works of Abraham (Jn 8:39). The modern day corollary is an unrepentant member of the Church who says to the Lord, “but Lord, I am a member of your church, the Church of Jesus Christ of Latter-day Saints.” He would reply, “If ye were a member of my Church, then ye would repent and come unto me.”
Conversely, it is possible for a non-Mormon to be considered part of His church if they have truly repented and come unto him. The point of this is not to say that non-Mormon followers of Christ don’t need the ordinances of salvation, but to show that when the Lord looks down from the heavens, he doesn’t just identify with the faithfulness of the Latter-day saints. He loves all of his children and considers many non-Mormons part of his flock. Those of us who are members of his recognized ecclesiastical organization must understand that membership alone does not equal recognition by the Lord. We must hear his voice and follow him in order to really be part of His church