Isaiah 5:12-13

They have lyre and harp, tambourine and flute, and wine at their feasts; but they do not regard nor even pay attention to the deeds of the Lord, nor do they consider the work of His Hands.  Therefore My people go into exile because they lack knowledge (of God): and their honorable men are famished, and their common people are parched with thirst.

The lack of knowledge of God to an unbeliever is an emptiness of the spirit that they can’t explain.  Because they don’t understand the love or working of God and have never connected to Him, they feel dry on the inside.  By our example and being a witness of Jesus, we can bridge the gap.  Even if we can plant a seed and another water, we can spread the gospel.