Isaiah 55:10-11: “As the rain and the snow come from heaven, and do not return to it without watering the earth and making it bud and flourish, so that it yields seed for the sower and bread for the eater, so is My word that goes out from My mouth: It will not return to Me empty, but will accomplish what I desire and achieve the purpose for which I sent it.”
Matthew 22:19-20: Seeing a fig tree by the road, He went up to it but found nothing on it except leaves. Then He said to it, “May you never bear fruit again!” Immediately the tree withered. When the disciples saw this, they were amazed. “How did the fig tree wither so quickly?” they asked.
John 15:5-6: “I am the vine, you are the branches. If you remain in Me and I in you, you will bear much fruit; apart from Me you can do nothing. If you do not remain in Me, you are like a branch that is thrown away and withers; such branches are picked up, thrown into the fire and burned.
Hebrews 6:7-8: Land that drinks in the rain often falling on it and that produces a crop useful to those for whom it is farmed receives the blessing of God. But land that produces thorns and thistles is worthless and is in danger of being cursed. In the end it will be burned.
TVs won’t work unless they’re plugged in. Microwaves can’t operate unless they’re plugged in. Computers and smartphones, though they have the capabilities to make available any kind of fathomable information right at your fingertips, will see their batteries die out unless they are plugged in. They are completely dependent on their power source. We’re not any different.
Like those household gadgets we too need to remain plugged into our source in order to operate in the capacity for which we were made. Our source is God. We can’t expect to fully function as the people He created us to be without His power in us.
God is the one who sustains us, provides us with purpose, and gives us His Holy Spirit so we can be fruitful in His kingdom. We can’t be fruitful apart from Him. 
If we are plugged in to Him and getting all of our power from Him, we should be fruitful. However, if we are plugged in to Him yet aren’t being fruitful, then that is a clear indication that something is amiss. If you just bought a TV, plugged it in, and then found that it wouldn’t even turn on, would you not get rid of it and get another one that works? The electricity in your house is working and all of the other electronics are operating just fine, so it’s very apparent that there’s something wrong with the TV. It’s really not that much different for us.
How can we be plugged in and commune with God and not be fruitful? That doesn’t make any sense. We are given every opportunity to connect with God and be fruitful. But if we neglect to do either of those things, we too will be like the fig tree that withered (Matthew 21:19-20), or the withered branches that didn’t remain in Christ (John 15:5-6), or the land that God provided rain to but risked being cursed because it produced “thorns and thistles” (Hebrews 6:7-8).
Plug into Him, remain in Him and be fruitful!