Unsuitable For Office

How does one tell the Church that someone is unsuitable for Church office? In a Catholic Church, or an Anglican Church, that might be accepted, but not in a Congregational Church. There is a culture of needing to know, based on spiritual equality. Yet that may conflict with a minister's need to be discreet. Part of a minister's effectiveness is his or her silence. Say, for instance, that someone has committed a dark sin. They can only talk about it, and be helped, if it will remain private. What then, if someone should nominate that same person for Church office? Or supposing that the person concerned is in office already. At the moment, someone I said was unsuitable for Church office is doing time. Which is far from saying that every person who is unsuitable for office should be doing time, or that one will always be right about suitability.