50 Christ enlightens His whole Church, as numberless passages from the Sacred Scriptures and the holy Fathers prove. "No man hath seen God at any time: the only-begotten Son who is in the bosom of the Father he hath declared him" Coming as a teacher from God to give testimony to the truth He shed such light upon the nascent apostolic Church that the Prince of the Apostles exclaimed: "Lord, to whom shall we go? Thou hast the words of eternal life"; from heaven He assisted the evangelists in such a way that as members of Christ they wrote what they had learned, as it were, at the dictation of the Head. And as for us today, who linger on in this earthly exile, He is still the author of faith as in our heavenly home He will be its finisher. It is He who imparts the light of faith to believers; it is He who enriches pastors and teachers and above all His Vicar on earth with the supernatural gifts of knowledge, understanding and wisdom, so that they may loyally preserve the treasury of faith, defend it vigorously, and explain it and confirm it with reverence and devotion. Finally, it is He who, though unseen, presides at the Councils of the Church and guides them.
Source: Mystici Corporis Christi (Vatican.va)