I have observed that in the scriptures when people were commanded something by vision, or by the Lord’s own voice, or by the Lord’s own presence, then disbelief or disobedience was visited with the most dire consequences.
However, certainly the Lord doesn’t send such manifestations simply to teach people things that they already knew or could have learned with just some additional insight into the scriptures. Certainly, there are many things to learn that run sharply counter to our traditions. Joseph Smith said “If the Church knew all the commandments, one-half they would condemn through prejudice and ignorance.”
This combination of things that run sharply against our traditions along with an enormous obligation to fully accept and obey may seem risky to us. After all, we know there are false manifestations and deceptive spirits.
And so I just wanted to point out the third member of this trio. The first part is that if we are ever so fortunate as to learn by a vision, or by the Lord’s own voice, or by his presence, there is an absolute requirement to believe and obey. The second part of the trio is that we will learn much that we did not expect, as heaven does not send its messengers to teach us things already found in the scriptures. The third part, the completion of this trio, is that God provides means for us to confirm the validity of any ministration as he lays out in D&C 129 and as is laid out in even greater detail in the temple endowment.
With a strict requirement to obey and to believe, the Lord also grants us a means to know with certainty whether any ministration be of God.