It's impossible to know everything there IS to know. The Bible even tells us that the world couldn't contain enough books with everything there is to know about the many things Jesus did.
John 21:25 And there are also many other things which Jesus did, the which, if they should be written every one, I suppose that even the world itself could not contain the books that should be written. Amen.
The Bible also says: Prove ALL things. (1 Thessalonians 5:21). But, how can I prove all things, if I don't KNOW all things!
For this reason, the Bible gives us the context of the "all things" in 2 Peter 1...
2 Peter 1:3-4 According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue: Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
The scriptures contain all the things that would help us to live a holy and godly life unto God. That is the specific context and meaning of the "all things."
God doesn't expect us to go to the Bible to find everything there IS to know. Instead, God expects us to go to the Bible to find everything we NEED to know.
All that you NEED pertaining to life and godliness is found in God's word!
Christ IS all!