"Advocate" is God Jehovah, who, by revealing His Will to man, by wooing, instructing, warning, cautioning him, so protects him from committing sin and its consequences.

"Defender" is a symbol of God's Will, His Covenants, the Commandments, the knowledge and fulfillment of which protects, saves man from an ungodly life of iniquity, of evil, of suffering and sorrow.  

"Protector" is a symbol of man's conscience and reason, which saves him from committing acts that lead to trouble, protects him from the destructive effects of pernicious ideologies, false teachings of the sinful world, from dangerous situations, from evil people.

"Protector" is a symbol of the sense of inner foresight, premonition, intuition sent by God to man, which in special cases reveals to man the way, the way to get rid of trouble.

Negative meaning.

"Protector" is a symbol of the various human, sinful, transitory, changeable laws, constitutions, statutes, false beliefs, scientific achievements, etc., which are created by man to protect him from remorse, from the consequences of a sinful life.

"Protector" is anything created not by God, which does not conform to His Will, but on which the sinfully living person relies in the hope of escaping God's punishment, and which   

cannot provide him with protection from committing evil, iniquities, and from experiencing their consequences.