No man is to be alone against Satan

“No man is to be alone against Satan; God instituted the church and the ministry of the Word in order that we might join hands and help one another. If the prayer of one does not help, the prayer of the other will.”

Martin Luther

Union with Christ is the foundation of all saints’ communion; and not any ordinances of Christ, or any judgment or opinion about externals

Now, concerning your admission of members… this much I think expedient…that after you are satisfied in the work of grace in the party you are to join with, the said party do solemnly declare (before some of the church at least), That Union with Christ is the foundation of all saints’ communion; and not any ordinances of Christ, or any judgment or opinion about externals…

John Bunyan on the examination of applicants for church membership, quoted in Faith Cook, Fearless Pilgrim: The Life and Times of John Bunyan, Evangelical Press, 2008, p.281-2