Should one assembly judge errors in another?

What should be our attitude to a neighbouring assembly, where moral or doctrinal evil is allowed to go on unjudged?

I presume what is meant by “moral or doctrinal evil” is something grave and fundamental, and not merely differences of judgement as to such questions as the exact rules to be followed at the Lord’s table, or regulations as to ministry. We have no authority in God’s Word as far as I can see, for cutting off an assembly, but we are not obliged to have fellowship with every assembly.

The Lord in His messages to the Seven Churches of Asia (Revelation 2: and Revelation 3: has to reprove Ephesus for “leaving her first love”; Pergamos for allowing among them those holding the doctrine of Balaam, or the doctrine of the Nicolaitanes; Thyatira for  “suffering that woman Jezebel.. . to teach and seduce God’s servants”; Sardis for dead-alive profession; and Laodicea for luke-warmness and self-satisfaction. Yet, though in each case appeal is made to him “who hath an ear to hear what is said unto the churches,” in no case is one church, or alliance of churches, instructed to deal in discipline with some other church.

Not even in the case of Smyrna or Philadelphia, with which no fault was found, is any such instruction given. Is there then nothing to be done? Clearly the exhortation “to hear” what is said to the churches, shows that no church should be indifferent to the state of other churches. Prayer for the erring church must be ever in season, and godly exhortation by word or letter always permissible. But what should be done if all prove abortive? Then all direct contact with the assembly as such must be avoided. It is she who is morally responsible for shutting her doors against those who stand for truth and righteousness. Can we imagine Smyrna having practical fellowship with Pergamos, or Philadelphia exchanging platforms with Thyatira? But the modem method, if we rule out “inferences” and “logical deductions”, of excommunicating churches or groups of churches, is profoundly foreign to Scripture.