It is necessary to check and see if one with whom you are thinking of associating is in the faith. It is prudent to have a dialog to make sure that you are on the same page on the major doctrines. It is exclusive and divisive to require specific pedigrees in order to acknowledge another’s faith. It seems to me that is little better than the folks that were demanding the circumcision of new believers in the early Church.
It is much better when the Body works together. Paul calls the Body, “the fullness of Him,” Ephesians 1:23. Think of that. As the Body of Christ, we are His fullness here. When we unite, when we pull together and encourage one another, help one another that fullness is focused and creates a much stronger impact.
It would be a good thing for all of us to be aware of the barriers we erect between believers. It would be a good thing for us to begin to pray we would see them and work to remove them.