Our courts go to great lengths to ensure that trials are as fair as possible. One way in which they do this is the thorough screening potential jurors are subjected to. This is intended to not only exclude those that have already made up their minds about the case but also weed out those candidates that have even a subtle bias that would prevent them from dispassionately evaluating the evidence and testimony presented in court. Should a potential juror that has already reached their own decision about the case misrepresent themselves during the screening process in order to sit on the jury, simply put, they have lied. They were selected under false pretenses and are quite literally, bearing "false witness" to the proceedings, a violation of the 9th Commandment (the 8th for Roman Catholics or Lutherans). Were such a thing to happen, and it unfortunately does from time to time, the juror is guilty of the crime of perjury.
The procedures used by our courts (screening of potential jurors, rules of evidence, rejection of hearsay, etc.) to ensure fair trials are simply a carefully delineated, formalized distillation of the rules for any kind of honest discussion. An honest discussion cannot take place if any party to it is not open to modifying or revising their views during the course of the dialog. To attempt to engage someone in what is billed as an "honest" discussion when ones own views on the subject at hand are off-limits to revision or modification is to misrepresent oneself, to lie.
At its heart, this is a moral issue. Religious believers frequently attempt to engage others in discussions in an attempt to persuade them of the "truth" of their particular dogma. They do this knowing full well that their own views are, at least as far as they are concerned, not open to revision or modification in the light of new arguments or evidence. The blatant duplicitousness and dishonesty of this must be publicly exposed and loudly condemned in no uncertain terms. Many believers seem to think that it is permissible to deceive others (not to mention themselves), either by lies of omission or commission, whenever it is believed to be justified by their beliefs. This double standard is morally and ethically reprehensible and something which should not be tolerated, either in the public square or in one's personal relationships.