The Spirit of Christ is the third person of the Trinity, having the same essence of deity as Jesus and as perfectly one with him as he is with the Father and helper-one literally called alongside to help, to encourage, and to exhort. Jesus says this comforter will take up residence in the believer. The title Spirit of Truth means that the Spirit is the source of truth and communicates the truth to his own.
(John 14:26, 16:12-15).
Apart from him, men cannot know God's truth.
(1 Corinthians 2:12-16; 1 John 2:20, 27).