What is "physical fruit"? "An outward evidence of the inward nature of the tree." (We know an apple tree is an apple tree because is produces apples).
Likewise, if we are walking in the Spirit, we will evidence His inward presence.
THE APPLE OF LOVE
In John 15:8, Jesus declared, "In this is My Father glorified, that you bear much fruit, so shall you be My disciples."
We glorify the Father and prove that we are followers of Jesus, when we produce the Fruit of the Spirit. The Fruit of the Spirit is