Passage
If any one abide not in me, he shall be cast forth as a branch and shall wither: and they shall gather him up and cast him into the fire: and he burneth.
If any one abide not in me, he shall be cast forth as a branch and shall wither: and they shall gather him up and cast him into the fire: and he burneth.
John 15:4 Abide in me: and I in you. As the branch cannot bear fruit of itself, unless it abide in the vine, so neither can you, unless you abide in me.
John 15:5 I am the vine: you the branches. He that abideth in me, and I in him, the same beareth much fruit: for without me you can do nothing.
John 15:6 If any one abide not in me, he shall be cast forth as a branch and shall wither: and they shall gather him up and cast him into the fire: and he burneth.
John 15:7 If you abide in me and my words abide in you, you shall ask whatever you will: and it shall be done unto you.
John 15:8 In this is my Father glorified: that you bring forth very much fruit and become my disciples.
The verse centers on "abide", "shall", "cast", "forth", "branch", and "wither". It is saying that the verse draws attention to "abide" and "shall", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 5's "I am the vine you the branches..." into verse 7's "If you abide in me and my...", so "abide" and "shall" 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 "abide" and "shall" with trust shaped by these words, not by a vague optimism outside the passage.