12 And whoso receiveth this record, and shall not condemn it because of the imperfections which are in it, the same shall know of greater things than these. Behold, I am Moroni; and were it possible, I would make all things known unto you.
In order to receive revelation from God, we must establish an appropriate frame of mind. A petty, critical attitude which fails to prioritize accurately, which focuses on small errors while ignoring the overall story, cannot lead us to wisdom. Moroni is teaching us here how to develop a productively inquiring mind and heart. “Don’t condemn me because of my little mistakes,” he says. Why? Because in doing so, we adopt a state of mind and heart which is incompatible with receptiveness to additional truth from God.
Note that he is not telling us to avoid critical thinking entirely. We need to be able to distinguish truth from error and to reject what is not right. The passage itself is an example of critical thought: teaching us what we should not do. But he is warning us to avoid critical thinking gone awry, a mental state which is so focused on identifying evil that it fails to recognize good. We ought to strive instead for a balanced mind which embraces truth and light even as it rejects error and which is primarily focused on the former, not on the latter.