At that time:
Jesus said to his disciples: All power is given to me in heaven and on earth. Go ye, therefore, and teach all nations: baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: teaching them to observe all things whatsoever I have commanded you; and behold I am with you all days, even to the consummation of the world.
Last Gospel.
St. Luke vi. 36-42.
At that time:
Jesus said to his disciples: Be ye merciful, as your Father also is merciful. Judge not, and you shall not be judged. Condemn not, and you shall not be condemned. Forgive, and you shall be forgiven. Give, and it shall be given to you: good measure and pressed down, and shaken together and running over, shall they give into your bosom. For with the same measure that you shall measure it shall be measured to you again. And he spoke also to them a similitude: Can the blind lead the blind? do they not both fall into the ditch? The disciple is not above his master; but every one shall be perfect, if he be as his master. And why seest thou the mote in thy brother's eye, but the beam that is in thy own eye thou considerest not? or how canst thou say to thy brother, Brother, let me pull the mote out of thy eye, when thou thyself seest not the beam in thy own eye? Thou hypocrite, cast first the beam out of thy own eye, and then shalt thou see clearly to take out the mote from thy brother's eye.
Sermon LXXXII.
Teach all nations:
baptizing them in the name of the Father,
and of the Son, and of the Holy Ghost.
—St. Matthew xxviii. 19.
The mystery of the Most Blessed Trinity is one of those wonderful truths of our holy faith which form the foundation of the Christian religion. He who does not believe in the Trinity cannot call himself a Christian; neither can any one be a Christian unless he is baptized in the name of the Father, and of the Son, and of the Holy Ghost. We are taught to make acts of profession of this mystery oftener than of any other. We do so every time we make the sign of the cross; and there are very few Catholics who do not make that sign more than once every day. Every one should know what is meant by the Trinity.
There is but one God, who is the infinite, eternal, almighty, all-wise, all-good, and all-just Being who created all things that exist.
But God, who is one in his Divine Being, is a Trinity in person. That is, he is three persons. These persons are named Father, Son, Holy Ghost. God is, then, Father, and he is Son, and he is Holy Ghost. These three persons are the same God. So, if there were three men praying to God, one praying to the Father, a second to the Son, and the third to the Holy Ghost, they would all be praying to the same God. How there can be more than one person in one being is a mystery to us, because we have no knowledge of any other being but God who has more than one person. But now this truth is revealed to us, we know, by our faith, which is divine knowledge, that there are three persons in God, and are sure also that God must, as a Divine Being, have three persons, because God cannot be other than he is. Let us help our minds to understand this by a comparison. Suppose a tower built in such a shape that it has three sides. Now, there are three distinct sides and only one tower; and whichever side we look at we see a distinct side which is not either of the other two sides, but we always can say, I see the tower. So, no matter which person of God we regard, it is always the same God.
Our holy faith teaches us that God the Father is the Divine Person who created all things, as we say in the Creed: "I believe in God, the Father Almighty, creator of heaven and earth." It furthermore teaches us that God the Son is the Divine Person who redeemed us by becoming man and dying on the cross, as the words of the Creed declare; and again it teaches us that God the Holy Ghost is the Divine Person who sanctifies us and is the source and giver of all grace. These truths are revealed to us, and we believe them, as we do all mysteries, for the reason we give when we make an act of faith: "O my God! I believe all things taught by the holy Catholic Church, because thou, who canst neither deceive nor be deceived, hast revealed them to her."