Passage
Now know we that thou knowest all things, and needest not that any man should ask thee: by this we believe that thou camest forth from God.
Now know we that thou knowest all things, and needest not that any man should ask thee: by this we believe that thou camest forth from God.
John 16:28 I came out from the Father, and am come into the world: again, I leave the world, and go unto the Father.
John 16:29 His disciples say, Lo, now speakest thou plainly, and speakest no dark saying.
John 16:30 Now know we that thou knowest all things, and needest not that any man should ask thee: by this we believe that thou camest forth from God.
John 16:31 Jesus answered them, Do ye now believe?
John 16:32 Behold, the hour cometh, yea, is come, that ye shall be scattered, every man to his own, and shall leave me alone: and [yet] I am not alone, because the Father is with me.
The verse centers on "all things", "thou", "knowest", "needest", "should", "thee", and "believe". It is saying that the verse draws attention to "all things" and "thou", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 29's "His disciples say Lo now speakest thou..." into verse 31's "Jesus answered them Do ye now believe...", so "all things" and "thou" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "all things" and "thou" with trust shaped by these words, not by a vague optimism outside the passage.