To remain in Him is to abide actively and also reciprocally. The branches without the vine can do nothing, they need the sap to grow and to bear fruit; but the vine, too, needs the branches, since fruit does not grow on the tree trunk.
Pope Francis
Jesus said to his disciples: “I am the true vine, and my Father is the vine grower. He takes away every branch in me that does not bear fruit, and every one that does he prunes so that it bears more fruit.
You are already pruned because of the word that I spoke to you. Remain in me, as I remain in you.
Just as a branch cannot bear fruit on its own unless it remains on the vine, so neither can you unless you remain in me.
I am the vine, you are the branches. Whoever remains in me and I in him will bear much fruit, because without me you can do nothing.
Anyone who does not remain in me will be thrown out like a branch and wither; people will gather them and throw them into a fire and they will be burned.
If you remain in me and my words remain in you, ask for whatever you want and it will be done for you. By this is my Father glorified, that you bear much fruit and become my disciples.”
John 15:1-8