1 John
I John 2:2 - Advocate is the same word used in John 14: 26 as Comforter.
Advocate - (forensic definition) The friend of the accused who voluntarily steps in and personally urges the judge to decide in his favor
Jesus Christ is our advocate who cares for our position as saints before God and against the accusations of the devil.
Comforter (common definition) one called alongside to help.
The Holy Spirit is the one called along side us to help in our daily walk of holiness. Whereas advocate deals with our positional holiness, Comforter deals with our practical holiness. Positionally I am declared righteous and holy according to the work of Jesus Christ. Practically I am not holy, but that is why the Holy Spirit is guiding me so that I am moving toward holiness.