Beforehand set up two tables next to each other. On one table build a structure with one set of blocks (the more complex the better); place a box over it to make sure it cannot be seen. On the other table provide a stack of blocks identical to the ones used to build your structure. Choose a child to come up to the table with the stack of blocks. Try to describe to him/her how to build the structure like yours. Once they have attempted it, remove your box and compare the two structures (theirs will differ considerably from yours.) Next have them try again to copy the structure with the box removed and looking at your example. They will be able to do it exactly.
Heavenly Father loves us so much and wants us to return home to Him, not only did he give us the scriptures to describe how to do it (like the first example), but He also sent His Son to show us what we need to do to gain eternal life (second example). Just like the blocks we are better able to copy something when we are shown how versus just being taught how.