Union With Christ: The Simile
Yes, Jesus used a simile to explain his union with believers. (Don't you love having a grammar lover for a teacher?)
In John 15, he told his disciples he is the vine and we are the branches. His reference was to grape vines. The vine is the strong trunk of the plant. Branches grow out of it and produce grapes. Jesus said to abide in him and produce fruit.
Only when we are attached to the true vine do we have life. In other words, when we are in union with Christ. That is because he is the source of life. Attached to him, we can produce the fruit of a Godly life. Separated from him, a person produces nothing but death. You can see this with any plant. I trimmed my rose bush. The main plant looked great. The branches I cut off turned brown and died.
All blessings and benefits flow from our union with Christ.