Psalm 52:7-8 King James Version (KJV) , 7 Lo, this is the man that made not God his strength; but trusted in the abundance of his riches, and strengthened himself in his wickedness. 8 But I am like a green olive tree in the house of God: I trust in the mercy of God for ever and ever.
The olive tree has many symbolic meanings. In the text the Hebrew word is zayith ( רַעֲנָן ׳ז ) meaning fresh, (thriving) olive-tree (simile of prosperity).
When an individual puts their just in their our strength and riches, they will be like the certain rich man in Luke 12:16-20 (KJV);
The tree of light: The olive oil was used as lighting oil and thus it was considered to be source of light.
The tree of wealth: For many families the olive trees and their products represent the main source of income.
When we put our trust in God we are thriving and prosperous in the house of God. This is exactly what GOD wants for his people.
For more information on the symbolism of Olive Trees go to oliveoilmani.com .
Picture is from http://www.explorecrete.com/nature/olive.html