This festival requires us to instruct the people in the dogma of the Holy Trinity, and to strengthen both memory and faith concerning it. This is the reason why we take up the subject once more. Without proper instruction and a sound foundation in this regard, other dogmas cannot be rightly and successfully treated. The other festivals of the year present the Lord God clothed in his works and miracles. For instance: on Christmas we celebrate his incarnation; on Easter his resurrection from the dead; on Whit-sunday the gift of the Holy Spirit and the establishment of the Christian Church. Thus all the other festivals present the Lord in the guise of a worker of one thing or another. But this Trinity Festival discloses him to us as he is in himself. Here we see him apart from whatever guise assumed, from whatever work done, solely in his divine essence. We must go beyond and above all reason, leaving behind the evidence of created things, and hear only God's own testimony concerning himself and his inner essence; otherwise we shall remain unenlightened.