i'm sometimes overwhelmed by things that i know a little bit about. follow my logic...
if i understand a little bit about something, i can see the quality or lack of quality in various parts of that whole. in an attempt to have better insight into a subject, i begin to explore. it's the exploration that overwhelms me. there are so many variables (which despite the popular philosophy of "endless possibilities", i know, mathematically, are limited) that my mind boggles to try and account for it all.
then, i feel like a failure for i know i should be able to understand it.
perhaps you've felt the same thing (i'm counting on it in order to make a point). so, let me re-tell my story from above, paraphrasing along the way.
when i understand a little bit about the bible, i can see the basic truths: God created everything, Jesus died for me, etc. some various parts of the whole impact instantly and others seem irrelevant or pointless. so, in an attempt to have better insight into the book as a whole, i begin to explore. the the exploration that overwhelms me. there are so many books and people and sins and do's and don'ts, etc. i know the book only has so many pages, but my mind boggles to try and account for a limitless God within a limited book--and that leads to more overwhelming due to pondering of divine mysteries: revelation, infinitism, omniscience. then, i feel like a failure for i know i should be able to understand it. (and then my feeling of failure conflicts me for i know that i have been redeemed.)
take heart. you are not alone, nor isolated in your feelings. God hears your frustration and He will enlighten you--only as much as you need or can handle in the moment. then, from that moment, He leads us to the next.
so, allow yourself to be overwhelmed by the Word of God. to know it is to be overwhelmed by it. take it in stride. take small bites, chew well and enjoy the feast for it does, truly, feed the soul.

Divine Author, we ask for Your insight today. help us to read with understanding and to understand for the purpose of sharing insight with fellow readers.