“The noun parakletos is derived from the verb parakaleo, “call for,” “make an appeal,” “comfort,” or “counsel.” Such noun formations are normally understood in a passive sense, i.e., “one who is called for or summoned” (cf. Lat. advocatus in the Vulg. of 1 Jn. 2:1). In John’s Gospel the Paraclete is introduced precisely as one summoned, a messenger sent from the Father in answer to Jesus’ prayer (Jn. 14:16; cf. also v.26; 15:26; 16:7). These considerations tend to justify such translations as “Advocate,” “Helper,” or “Mediator.” But because parakaleo is an important verb in the NT, some scholars have argued that the verbal noun has an active sense: “one who appeals, counsels, or consoles”; hence the popular translations “Comforter” or “Counselor.”
Undoubtedly the Paraclete in John’s Gospel does carry out some functions that are aptly expressed by the verb parakaleo. Yet the Paraclete’s role is best understood not by sketching the range of meaning of parakaleo (which does not occur in the Johannine writings) but by noting the verbs actually used by John to describe what the Paraclete will do:
(1) In relation to Jesus’ disciples, the Paraclete will be with them forever (14:16f.) to teach and remind them of what Jesus has already taught (v. 26). “He” (the masculine article and pronoun indicate personality, not gender) will testify to them, and through them to the world, about Jesus (15:26f.). He will guide them into all the truth and will glorify Jesus by speaking what He hears from the Father. He will even predict things to come (16:13-15).
(2) In relation to the world, the Paraclete will act as God’s advocate, to convict the world of sin and prove it wrong in its standards of justice and judgment (16:8-11).
Geoffrey W. Bromiley, International Standard Bible Encyclopedia: K-P
Wm. B. Eerdmans Publishing Company (Jan. 1995), pg. 660