1. This epistle is read today because the festival of Holy Trinity, or of the three persons of the Godhead--which is the prime, great, incomprehensible and chief article of faith--is observed on this day. The object of its observance is that, by the Word of God, this truth of the Godhead may be preserved among Christians, enabling them to know God as he would be known. For although Paul does not treat of that article in this epistle, but touches on it only in a few words in the conclusion, nevertheless he would teach that in our attempts to comprehend God we must not speculate and judge according to human wisdom, but in the light of the Word of God alone. For these divine truths are too far above the reach of reason ever to be comprehended and explored by the understanding of man. 2. And although I have, on other occasions, taught and written on this article fully and frequently enough, still I must say a few words in general concerning it here. True, it is not choice German, nor has it a pleasing sound, when we designate God by the word "Dreifaltigkeit" (nor is the Latin, Trinitas, more elegant); but since we have no better term, we must employ these. For, as I have said, this article is so far above the power of the human mind to grasp, or the tongue to express, that God, as the Father of his children, will pardon us when we stammer and lisp as best we can, if only our faith be pure and right. By this term, however, we would say that we believe the divine majesty to be three distinct persons of one true essence. 3. This is the revelation and knowledge Christians have of God: they not only know him to be one true God, who is independent of and over all creatures, and that there can be no more than this one true God, but they know also what this one true God in his essential, inscrutable essence is. 4. The reason and wisdom of man may go so far as to reach the conclusion, although feebly, that there must be one eternal divine being, who has created and who preserves and governs all things. Man sees such a beautiful and wonderful creation in the heavens and on the earth, one so wonderfully, regularly and securely preserved and ordered, that he must say: It is impossible that this came into existence by mere chance, or that it originated and controls itself; there must have been a Creator and Lord from whom all these things proceed and by whom they are governed. Thus God may be known by his creatures, as St. Paul says: "For the invisible things of him since the creation of the world are clearly seen, being perceived through the things that are made, even his everlasting power and divinity." Rom 1, 20. This is (a posteriori) the knowledge that we have when we contemplate God from without, in his works and government; as one, looking upon a castle or house from without, would draw conclusions as to its lord or keeper.