6 The greater part of humanity were toiling in this abyss of misery, and were the more to be pitied because they were sunk in the darkness of superstition, when in the fullness of time and by the designs of God, light shone down upon the world, and the merits of Christ the Redeemer were poured out upon mankind. By that means they were lifted out of the Slough and the distress of slavery, and recalled and brought back from the terrible bondage of sin to their high dignity as the sons of God. Thus, the Apostles, in the early days of the Church, among other precepts for a devout life taught and laid down the doctrine which more than once occurs in the Epistles of St. Paul addressed to those newly baptized: "For you are all the children of God by faith, in Jesus Christ. For as many of you as have been baptized in Christ, have put on Christ. There is neither Jew, nor Greek; there is neither bond, nor free; there is neither male nor female. For you are all one in Christ Jesus."(7) "Where there is neither Gentile nor Jew, circumcision nor uncircumcision, barbarian nor Scythian, bond nor free. But Christ is all and in all."(8) "For in one Spirit were we all baptized into one body, whether Jews or Gentiles, whether bond or free; and in one Spirit we have all been made to drink."(9) Golden words, indeed, noble and wholesome lessons, whereby its old dignity is given back and with increase to the human race, and men of whatever land or tongue of class are bound together and joined in the strong bonds of brotherly kinship. Those things St. Paul, with that Christian charity with which he was filled, learned from the very heart of Him who, with much surpassing goodness, gave Himself to be the brother of us all, and in His own person, without omitting or excepting any one, so ennobled men that they might become participators in the divine nature. Through this Christian charity the various races of men were drawn together under the divine guidance in such a wonderful way that they blossomed into a new state of hope and public happiness; as with the progress of time and events and the constant labor of the Church the various nations were able to gather together, Christian and free, organized anew after the manner of a family.
Source: In Plurimis (Vatican.va)