Jacob Chapter 4

4:6 - "...we search the prophets, and we have many revelations and the spirit of prophecy; and having all these witnesses we obtain a hope and our faith becometh unshaken..."
This is not how we first receive faith, but how our faith can grow.  If we study, act, and hope, we will develop our faith and become unshakeable.  We know it's important to have faith because it helps us develop other attributes and understanding...we just need to remember that we have to develop faith, too.

4:6-8 - "...we search the prophets, and we have many revelations and the spirit of prophecy; and having all these witnesses we obtain a hope, and our faith becometh unshaken, insomuch that we truly can command in the name of Jesus and the very trees obey us, or the mountains, or the waves of the sea..."
As we search the prophecies, receive revelations, and receive the spirit of prophecy, we receive also a hope, a faith that becometh unshaken, and we can command in the name of Jesus and the very trees obey us, or the mountains, or the waves of the sea.  We can do those things, but we need humility!  God shows us our weakness that we can be made strong.  Our weakness is our distance from God (Ether 12:27).
I wonder what we could do and how we could help others if we followed the requirements and had enough faith to move mountains.

4:8 - "...no man knoweth of his ways save it be revealed unto him..."
Elder Richard G. Scott talked about this in the November 2007 Ensign, Pg. 90-92. "The best way of finding truth is simply to go to the origin of all truth and ask or respond to inspiration.  For success, two ingredients are essential: first, unwavering faith in the source of all truth; second, a willingness to keep God's commandments to keep open spiritual communication with Him."
This is how we can and will receive revelation.

4:13 - "...behold, my brethren, he that prophesieth, let him prophesy to the understanding of men..."
We need to understand what is being taught so we can apply it.  That's why it needs to be plain (Alma 5:43).  When we search beyond the mark, the plainness is taken away and we dive into confusion.  That's not how we want to end up.  Sticking with the basic doctrines and principles of the gospel will help us understand all we need to understand.
The distance to Kolob is not important right now.  Having faith enough to move mountains...that's more important.

4:16-18 - "...how is it possible that [the Jews], after having rejected the sure foundation, can ever build upon it..."
The Jews (in general) rejected Jesus Christ...how can they build again upon that foundation...or the head of their corner? (Psalms 118:22).  The answer lies within Jacob 5.