Passage
I have yet many things to say unto you, but ye cannot bear them now.
John 16:12 (ASV)
Nearby Context
John 16:10 of righteousness, because I go to the Father, and ye behold me no more;
John 16:11 of judgment, because the prince of this world hath been judged.
John 16:12 I have yet many things to say unto you, but ye cannot bear them now.
John 16:13 Howbeit when he, the Spirit of truth, is come, he shall guide you into all the truth: for he shall not speak from himself; but what things soever he shall hear, [these] shall he speak: and he shall declare unto you the things that are to come.
John 16:14 He shall glorify me: for he shall take of mine, and shall declare [it] unto you.
Study Lenses
The verse centers on "things" and "bear". It is saying that the verse draws attention to "things" and "bear", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 11's "of judgment because the prince of this..." into verse 13's "Howbeit when he the Spirit of truth...", so "things" and "bear" 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 "things" and "bear" with trust shaped by these words, not by a vague optimism outside the passage.