In my mind, lasting significance can only come from one place, and that place is God. If we are looking for significance that is apart from Him, I believe we may find a certain degree of meaning, but how fruitful it will be is another question. In order for something to be truly fruitful it must feed us and others. It must be significant enough that we can return to it time and time again. In returning we will find what we are looking for, and have what we need. To me this is a real demonstration of fruit.
Fruitful significance should be able to sustain us in famine and drought, but it also must have meaning in times of plenty. It may be personal to our calling, but it should witness to others.
When Jesus went to pick a fig from a tree, and found no fruit, He cursed the tree declaring that it would never bear fruit again. His disciples were with Him, so they were a witness to this encounter first hand. When they later observed the tree, it had indeed dried up and withered from the roots. Never again would it produce figs.
Jesus was teaching His disciples a valuable lesson here. It might look as if Jesus was cursing the tree out of anger when it did not give Him what He desired, but the lesson was actually deeper. Jesus was illustrating the power in our words, when we believe and do not doubt, what we ask will be given to us.
Fruitful significance comes from speaking words that bear witness to the power of God, and His truth. They are words that feed the deep longings in our souls and become a critical part of our spirit man. These words do not die, but they go out and bear much fruit. It is the kind of fruit that really does sustain us in all times, and in all ways.
Fruitful significance is in the power of the tongue, and comes from speaking the promises of God. It is believing that we speak truth, and remembering that God's truth will always produce that which is good.
Mark 11:23-24 NIV "Truly I tell you, if anyone says to his mountain, 'Go throw yourself into the sea,' and does not doubt in their heart but believes that what they say will happen, it will be done for them. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours."