Then the belief will never change. The only way to change a theology is to change its practice AND words of instruction.
A teacher can't give their students a test about a new way of doing things after the students learn from an old way. New bricks on an old foundation will collapse in heaps of rubble; from confusion and unacceptance. You must break down what is old for the whole foundation to hold up the new layers of bricks. Only in this way will the wall be sturdy enough to withstand the stress of outside forces, or to be integrated into other walls.
The stress that NEW Mormonism must endure is of other religions changing them. Religions that mostly agree with NEW Mormonism (if it is built correctly) will not try to tear it down. Religions that are against it will bash with all their might. Confusion and moral incorrectness in and between OLD and NEW Mormonism will cause it as a whole to fall apart.
Integrating with new walls is how Mormonism could maybe one day fit like how Catholicism, Protestantism and Orthodox Christianity fit together. They are essentially the same religion with few (maybe a few more than a few) minor differences but ultimately believe the same thing: Jesus is Lord and should we believe in him and, we will be saved. While believing in Jesus, we are obligated to try to be like him in his teachings that are mostly, if not all, agreed on by Catholicism, Protestantism, and Orthodox Christianity. Mormonism as it is now, does not agree at least mostly with these. Especially the written teaching of polygamy.