Literary: In this short passage Jacob does some intricate logic work. He begins by praising God. The praise lauds the works of God. For the nice shifting of ideas that will follow, what is important in this statement of praise is that it is impossible to praise God's works without understanding that there is some connection between God and man. This is a God who is not completely removed, but demonstrates His connection to man through works in his favor (and those works need be no more than the spectacular provision of the world and man's existence).
Having established a God of works with a relationship to man, Jacob notes that God is yet separate from us in such a way that we cannot comprehend all of the purposes of God. Thus while we may see that some of his works are wonderful, we yet find both God and many of his works to be mysterious and hidden from comprehension. In this Jacob echoes Isaiah: "Isa. 55:8-9 For my thoughts are not your thoughts, neither are your ways my ways, saith the LORD. 9 For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts."
Jacob has now set up a neat logical and philosophical problem. He has declared a God that is interested in us and does works that are directed towards us, yet is utterly incomprehensible to us. How shall we please a God we cannot understand? How might man properly interact with a God who is unfathomable? Jacob tells us that there is no way save revelation from God to the prophets. However, there are prophets, and therefore it behooves us to search them. We ignore those prophets only to our peril, for without the we are unable to understand how to relate to this God who can and doe, work marvels that are directed to us, but which often require special understanding to comprehend.