Underground springs often provide water for fertile areas even when there's no water present on the surface. Sometimes these areas become bogs or swamps, lowlands where the water bubbling beneath the ground doesn't drain away. Vegetation and animal life flourish there even though it might look surprisingly calm at first glance. Often, change and growth take place even when we can't see it.
The same is true with our spiritual lives. God's Spirit within us provides a wellspring of Living Water to nourish and sustain us. And while we may not feel as though we're becoming more mature or deepening our faith as we walk with the Lord, growth is taking place nevertheless.
Our Father provides everything we need to grow. His Spirit is at work even when we can't see what's going on.