An application of consistency shows that a pattern may exist. It is not definitive proof especially when you are dealing with the Word of God. Because it is all written out in black and white, it should be easier for you to prove your case instead of relying on “an application of consistancy”.
Application of consistency? HAH! I am waiting to hear how Mormonism Apologists justify Smith abrogating marriage vows by taking women to wife who were still married to alive men with whom they had taken vows and Smith’s vows in his marriage to Emma set aside by marrying more married women! This stinks to high Heaven, and the apologists just keep getting more into their Gordian Knot of deceit in order to defend this Smith and his successors.
To do what you demand, we would have to rely on modern revelation. As you don’t accept that as valid, I’m limited to works that you will find acceptable.
If we were to expand the scope to include what I believe to be scripture, the doctrine would be most plain to comprehend. Alas, we Mormons are hobbled in this fashion.
Still, the fact remains that sanctioned polygamy demonstrably existed in the Old Testament. You object to that doctrine being revisited in modern times, and that’s fine; but it has been demonstrated that polygamy, in and of itself, is not immoral when administered under the Lord’s directives.