Just before Jesus offered up his life for us, he said, “I will ask the Father, and he will give you another advocate to help you and be with you forever – the Spirit of truth.” Jesus, the Father’s Son, asks the Father for the Spirit of truth to guide us into all truth.  

The “truth” into which the Spirit guides us is not abstract concepts or a set of doctrines. Jesus declares, “I am the way, the truth, and the life.” Therefore, truth is not something but Someone — Jesus himself. He is the truth about God, showing us the Father’s heart, and he is the truth about humanity, revealing who we are called to be in communion with God. To know the truth, then, is to know Jesus personally and in knowing Jesus, we know the truth that sets us free.

But the truth of the Father through the Son comes to us by the Spirit of truth.  The Spirit of truth brings Jesus, the truth, to us so that we see him with the eyes of our hearts.  He is “the Spirit of truth” sent by the Father and Son to lead us into all truth.  
The Spirit comes within us, shining the light of the Son right into the depths of our hearts so that we see the glory of God in his face. He is “the Spirit of truth” sent by the Father and Son to lead us into all truth.  The Spirit of truth can do this in us because he is Himself God, true God of true God. And so, he alone can bring Jesus, the truth of God, to us