Jesus tells us, The Holy Spirit who the Father will sent you in my name will teach you everything.

But the Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you" (Jn 14:26). The Holy Spirit will be the Counselor of the Apostles and the Church, always present in their midst—even though invisible—as the teacher of the same Good News that Christ proclaimed. The words "he will teach" and "bring to remembrance" mean not only that he, in his own particular way, will continue to inspire the spreading of the Gospel of salvation but also that he will help people to understand the correct meaning of the content of Christ's message; they mean that he will ensure continuity and identity of understanding in the midst of changing conditions and circumstances. The Holy Spirit, then, will ensure that in the Church there will always continue the same truth which the Apostles heard from their Master.