Read Jeremiah 17.
A sure sign of life is health and growth. Sin will destroy both in one's spiritual life. Those who place their faith in man-made schemes, instead of exclusively trusting God, will pay a severe price.
In verse 6, Judah's spiritual condition is compared to a shrub in the desert. With no sustenance, the shrub produces nothing of any value. The plant is pictured as being alone in salty soil that actually kills life.
The opposite is true of those trust in the LORD (vv.7-8). They stand like a tree, not a shrub. They have been planted where the roots are well watered and the environment does not affect its vitality. In verse 13, the LORD is called "the fountain of living water."
This chapter serves as a bridge passage between Psalm 1 and John 4.
Psalm 1:3 describes the one who constantly delights in God's word as "a tree planted by streams of water that yields its fruit in its season, and its leaf does not wither. In all that he does, he prospers."
Jesus spoke to the woman at the well in John 4:10, 13-14 and said, "If you knew the gift of God, and who it is that is saying to you, 'Give me a drink,' you would have asked him, and he would have given you living water." "Everyone who drinks of this water will be thirsty again, but whoever drinks of the water that I will give him will never be thirsty again. The water that I will give him will become in him a spring of water welling up to eternal life."