A Covenant is a Covenant

Let us posit for the moment that Mormonism is not true, but that some other religion is. I am curious about how LDSs will be judged with respect to the covenants they have made. Mormons have made covenants before God to follow certain teachings. How will Mormons who have broken those covenants be judged? Will it be to their advantage because Mormonism is false? How about Mormons who have kept those covenants? Will they be rewarded because they kept the promise that they made to God?

I suppose that the same question is valid if Mormonism is true with respect to the vows and commitments made by others. How will the vows of a Buddhist monk be evaluated by God?

Part of the reason that I am asking this question is whether or not the fact that one has made a covenant to do so is a sufficient reason for someone to remain active in the church. Thoughts?