The fundamental truths of the restored gospel were not delivered to the Prophet Joseph Smith all at once in the Sacred Grove. These priceless treasures were revealed as circumstances warranted and as the timing was right.
There are many things that the leading men of this Church can see and understand that they cannot impart to the people nor ask the people to do. Why? Because they know that the people would not come up to the requirement and that therefore they would be disobedient. Better to give them line upon line, precept upon precept, here a little and there a little than to give them something that they could not receive and that they would rebel against. That is the manner in which the Lord deals with His children, and it is the manner in which wise men inspired of the Lord deal with their fellow men.