The Bible teaches us that “The blessed man is like a tree planted by the rivers of water, who brings forth his fruit in his season, and his leaves does not wither and in whatsoever he does, he prospers.” (Psalm 1:3).
A tree that is planted by the rivers of water implies that the tree has perpetually proximity to water, which is a primary source of its life. Jesus said, I am the resurrection and THE LIFE (John 11:25) and his Holy Spirit is the living water that flows out of those who have believed and received Jesus Christ (John 4:13-14). A blessed man, is one who is perpetually in proximity to Jesus Christ, the author and personification of life.
Not only is he watered by the Holy Spirit of God, the blessed man is also fruitful in his mission of reconciling God to man. Just as a mango tree will bear only mango fruit and not any other kind of fruit, the fruit of a believing blessed person and can only be another believer who will also be blessed. Unlike the fig tree that was worthless to the owner of the vineyard, but fit only to be cut down for being fruitless (Luke 13:6-9), the man who is fruitful brings joy to the owner of the vineyard, producing many others who believe in the name of the Lord Jesus Christ; much fruit in thirty, sixty and hundredfold.
Additionally, just as leaves are a source of medicine that brings healing (Revelation 22:12; Ezekiel 47:12), the blessed man is unwithering in his mission of bringing healing to the nations; healing from the sickness of sin and the power of death, by pointing others to Jesus Christ, the master physician and healer of all mankind.
Psalm 1:3 (KJV)
3 And he shall be like a tree planted by the rivers of water, that bringeth forth his fruit in his season; his leaf also shall not wither; and whatsoever he doeth shall prosper.