Passage
These things have I spoken unto you, that my joy might remain in you, and that your joy might be full.
John 15:11 (KJV)
Nearby Context
John 15:9 As the Father hath loved me, so have I loved you: continue ye in my love.
John 15:10 If ye keep my commandments, ye shall abide in my love; even as I have kept my Father’s commandments, and abide in his love.
John 15:11 These things have I spoken unto you, that my joy might remain in you, and that your joy might be full.
John 15:12 This is my commandment, That ye love one another, as I have loved you.
John 15:13 Greater love hath no man than this, that a man lay down his life for his friends.
Study Lenses
The verse centers on "things", "spoken", "might", "remain", and "full". It is saying that the verse draws attention to "things" and "spoken", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "If ye keep my commandments ye shall..." into verse 12's "This is my commandment That ye love...", so "things" and "spoken" 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 "spoken" with trust shaped by these words, not by a vague optimism outside the passage.