Paul's evangelistic mission was different from the Kingdom Apostles, but in many ways the same. The Kingdom Apostles preached Jesus the Messiah, ready to return to Israel and set up His Messianic Kingdom. From Israel, the Apostles, with Christ on David's Throne, were to go into all the world and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to observe everything Christ had commanded them. They would do that because all authority in heaven and on earth had been given to Christ. As we all know, that did not happen. It will happen in the future, but it has not yet happened. What has happened is that Christ revealed a Mystery through His Special Apostle Paul.
The angels are so enamoured of the language that is spoken in heaven, that they will not distort their lips with the hissing and unmusical dialects of men, but speak their own, whether there be any who understand it or not.
The book which the reader now holds in his hands, from one end to the other, as a whole and in its details, whatever gaps, exceptions, or weaknesses it may contain, treats of the advance from evil to good, from injustice to justice, from falsity to truth, from darkness to daylight, from blind appetite to conscience, from decay to life, from bestiality to duty, from Hell to Heaven, from limbo to God. Matter itself is the starting-point, and the point of arrival is the soul. Hydra at the beginning, an angel at the end.