John-15:5 (Jesus speaking) I am the vine, you are the branches. Whoever abides in me and I in him, he it is that bears much fruit. Apart from me, you can do nothing. (ESV)
This verse about the branches staying attached to the vine is a beautiful picture. When branches no longer are connected to the vine, there is no possible way they can grow leaves or any other kind of fruit. But when they are attached, they will begin to produce fruit. In a similar sense, Jesus is basically telling his disciples in this passage to stay connected to Himself the vine. Seek the Lord. Love Him with all their heart.
He also says that apart from the vine the branches can do nothing. When we are disconnected or not pursuing Jesus, we can do NOTHING of true value to the kingdom. But when we are abiding in Jesus, we can do EVERYTHING. When we are abiding, fruit will abound in our lives. The fruits of the Spirit will naturally flow through us.
One other thing I want to mention is in verse 2 Jesus mentions that everyone that produces fruit will be pruned by the Father. I can only imagine how much being pruned would seem to hurt the branch, but it is necessary that we might bear more fruit. So if your are abiding in Christ, but things seem to be getting harder, take heart that the Father is pruning you to bear more fruit. But if you are depending on your own strength today, humble yourself before the Lord and admit your need for Him.