Yes.
You need to be perfect.
And that means -- to the Mormon -- fulfilling ALL of your covenants, your sealings, your obligations, your rituals, etc.
If you can't get into the temple, then none of the temple endowments and temple sealings & rituals can be performed. That includes marriage for eternity and having your kids sealed to you. And without all that, there's no "Family" for you to populate your own planet.
Just who believes all this fantastical poppycock!!?
Oy!
Of the current number of Mormons through out the world what percentage meet those rigorous requirements?