Growth and increase and maturing of the fruit......process of sanctification, as I understand it. God's work in our lives as well as our part in submitting to His work and seeking to grow - like the growth and ripening of fruit to its peak of perfection. Fruits include good works as well as Christ-like character traits. And the Lord prunes even the fruitful branches to make them more fruitful. The long and the short of it is that He does it through suffering.
2Co 7:1
Having therefore these promises, dearly beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God.
Luk 8:14
And that which fell among thorns are they, which, when they have heard, go forth, and are choked with cares and riches and pleasures of this life, and bring no fruit to perfection.
Col 1:10
That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God;
Heb 13:21
Make you perfect in every good work to do his will, working in you that which is wellpleasing in his sight, through Jesus Christ; to whom be glory for ever and ever. Amen.
Jhn 15:2
“Every branch in Me that does not bear fruit He takes away; and every branch that bears fruit He prunes, that it may bear more fruit.
Mar 4:26-29
And he said, So is the kingdom of God, as if a man should cast seed into the ground;
And should sleep, and rise night and day, and the seed should spring and grow up, he knoweth not how.
For the earth bringeth forth fruit of herself; first the blade, then the ear, after that the full corn in the ear.
But when the fruit is brought forth, immediately he putteth in the sickle, because the harvest is come.