The requirement of independent confirmation is not waived simply because a person confesses to something. That independent confirmation may certainly be circumstantial, but authorities in any realm ought to be wary of simply accepting someone’s accusation against himself.
Say that a man, wracked with guilt, confesses to a murder. He goes to the police and confesses to having murdered someone the year before. The details of his story still have to be checked out, and the rules of evidence still have to be remembered while doing it. If he shows the police where the body is buried, and it becomes independently clear that this confession is accurate, then he can and should be charged. But if the only thing to go on is the confession, then it is not good enough. Why is this?
There are a number of reasons, and the thought behind the well-known action of “pleading the fifth” is a thoroughly biblical one. The fifth amendment allows us (in the civil realm) to refrain from making any statements that might tend to incriminate us, and holds further that we may therefore remain silent without that silence being used as evidence of guilt. Why is this a scriptural principle? Or, better stated, why is this a healthy reflection of a biblical principle?
In the civil realm, a man can be worked over with rubber hoses until he decides that ten years in the Big House would be preferrable to the treatment he is getting. If we allow a simple confession to suffice for conviction, and nothing confessed has to line up with the way things are in the external world, then we have opened the door to thumbscrews. This was not an academic worry for our founding fathers, and neither is it an academic worry today.
What about in the church? There are churches where the rubber hoses are not made out of rubber, but they still work pretty well. All sorts of pressures can be brought to bear on someone under authority, and one of the central protections for the individual is a corporate and institutionalized understanding (on the part of everyone) that a solitary confession is not enough to convict anyone of anything. To simply allow people to come forward as their own accusers (and to require nothing more) is to affirm the Stalinist show trials as textbook models of justices. And even if we take away the capacity for physical coercion that Stalin had, the ecclesiastical world is not lacking men like Diotrephes, who loved to have the preeminence (3 John 9), or elders who neglect Peter’s admonition (1 Pet. 5:3), and who lord it over the flock. Jesus thought that power-manipulation was going to be enough of a temptation in the church that He explicitly warned His disciples against ruling the way pagan civil rulers did. Tyrants in any realm can always say, “Vee haff vays . . .” And they do. This is why maintaining tight views of what constitutes justice (in every direction) is so essential to life together. Without it, eveythings tumbles into genuine fears and weird paranoias.
There are other reasons to be wary about self-incrimination in the church, even assuming no authoritarianism. People confess to things for different reasons, and in various states of mind. Suppose someone confesses to a particular sin, but they do so while in the throes of a black depression. Should the pastor or elders simply take the confession and proceed as though it was necessarily true? I can think of at least one instance where I am extremely grateful that I did not do this. Suppose someone is in a relationship with a very manipulative person, and the person in question is manipulable. Say the husband is unfaithful, and yet he has his wife so browbeaten that she blames herself for his infidelity. Will her confession of her resposibilities be an accurate assessment of the situation? Almost certainly not.
There are any number of ways that problems like this could develop, and a third example comes to mind. Suppose the confession is taken out of context, and placed in a different setting entirely. Say that a husband with a sensitive conscience goes to the grocery store to buy a loaf of bread. While standing in the checkout line, he notices the lady on the front of Cosmopolitan acting like a sale at Dillards — forty percent off. And let us say that he does more than notice her, and he gives way to unbridled lust. But by the time he gets out to his car, his senses come back to him, and he is overwhelmed with remorse. He then gets home and confesses “infidelity” to his wife. Now presumably he explained the context to her, and exactly what it is he is confessing to. But he knows that Jesus taught that lust in the heart is equivalent to adultery, and so he confesses it in that way. He broke the seventh commandment. Later in the evening, he follows this up with a note written in a card, seeking forgiveness again for his “infidelity.”
Now all this is fine, so long as neither he nor his wife are obsessing about it (which people with sensitive consciences frequently do, incidentally). But suppose the wife takes the note he wrote down to the pastor, shows it to him, and wants to know if the church will allow her to divorce her husband. There it is, in black and white. He came as his own accuser, and confessed to having broken the seventh commandment, and is guilty of infidelity. And Jesus taught that infidelity is one of the few scriptural grounds for divorce. So, can she have a divorce? No.
Faithful Christians (particularly faithful Christians who have read some of the Puritans) frequently confess sin in a robust way, pushing their confession into all the nooks and crannies identified by the Westminster Larger Catechism. But to take a confession from one context and place it in another context (e.g. from a note of apology to divorce court) without bringing in all the other principles of justice is negligence at best and gross injustice.
This is simply because when the man apologized for sin X he was not seeking forgiveness for sin Y. This would become immediately apparent if the principle of Proverbs 18:17 were remembered, and poof, there goes the grounds of divorce. This mistake is a variant of the fallacy of equivocation, the fallacy where the meaning of the terms changes in the middle of the argument: “God is love. Love is blind. Ray Charles is blind. Therefore . . .” But in this case it is the meaning of words and phrases that are changed by placing them in a different context.
When men want justice, they must deliberate. They must go slowly. They must sleep on it. They must ask questions, and allow those who differ with them to ask their questions as well. They must be eager for this, and not resent it. And until there is overwhelming evidence, checked, cross-checked, and tied down with baling wire, the accused didn’t do anything wrong. This is what is meant by “beyond a reasonable doubt.” But remember that the Scripture brings in a host of principles that require us to expand this phrase, making the hermeneutical assumption within it explicit. A man should not be convicted unless the evidence requires it beyond a reasonable doubt, when considered by reasonable people. And reasonable people are defined by Scripture and not their own assessments of their own wisdom.