"I have much more to say to you, more than you can now bear. But when He, the Spirit of Truth comes, He will guide you in all truth. He will not speak on His own He will speak only what He hears and He will tell you what is yet to come" (John 16:12-13).
It is so easy to get overwhelmed when you begin to realize how big the gap is between what you do know and what you need to know. Jesus was being sensitive to the growing concern of the disciples, that perhaps they were not ready to continue on in this pioneering journey that He had been preparing them for. he was comforting them. Even though He was leaving this earth, and even though there was still so much more they needed to learn from Him, He would send the Holy Spirit. He would never leave them "high and dry." The success of the mission He was investing in them depended upon Him fully equipping them, thus investing in its very success.
The Holy Spirit would guide them in all Truth. He would be the "headlights" that would illuminate the path as they journeyed through spiritual landscapes they hadn't yet fully known. Because of this promised Comforter, they would never have to feel lost, alone, or overwhelmed.
Each day, it is so easy to reminded of that great chasm that separates us from where we are and where should be; what we know, and what we have yet to learn. And, though the temptation to give into the emotions that overwhelm like the crashing of a wave, we can stand tall with confidence and filled with a peace that passes all understanding. Because, if His Spirit lives in us, then we have access to everything God wants us to know at just the time He's like us to know it.
Don't allow yourself to become overburdened with all of the things about God that you "should" know, but you don't. Don't allow those thoughts in your mind that seek so hard to convince you that it's just too much, it's all made up, or, you'll never be able to "master" this anyway. Rather, continue to run to Him, rest in Him, and depend upon the leading and guiding of the light of His Holy Spirit.