Not bearing fruit is a serious thing. This parable is a bit scary to me.
Am I bearing fruit? Are you bearing fruit?
If we go to John 15:16 Jesus says the reason He chose us and appointed us was to "go and bear fruit."
And if you remember the poor fig tree Jesus looked to for fruit. When He didn't find any He killed it.
We can't force ourselves to bear fruit anymore than a literal fruit tree can force itself to bear fruit.
BUT, we can allow ourselves to bear fruit.
By using everything God brings into our lives to draw closer to Him; to let Him change us; to yield when He asks us to yield; to rest in Him all the time; to soak in the spiritual nutrients found in every situation God brings us into and through; to not waste one second in pity. Instead do all things for Him knowing He will bring you through.
This is how we bear fruit. When we fight against God almighty the most He can do is speak truth and continue to persuade us to choose Him. He won't force us. Force doesn't bring fruit. Force brings about bitterness.
Yield and bear fruit today.