St. Louis de Montfort makes it clear that the entire purpose of our lives is to unite ourselves to Our Lord Jesus Christ. God willed from all eternity to send His Son for the Redemption of mankind.
Our Lord is “the Way, the Truth, and the Life.” And “There has been no other name given under Heaven by which we can be saved, except the name of Jesus.”
Mankind was totally lost before the coming of Our Lord. Unless those of the Old Testament believed and hoped in the Messias to come, who was not yet revealed and whom they did not know personally, they could not be saved. Even in the Old Testament, then, there was no salvation outside Our Lord Jesus Christ.
Since Our Lord’s coming, every man must make a choice either to stand with Him or be against Him. There is no third possibility. Those who are outside of Him are in error, are with the father of lies, are children of the devil. If we are with Our Lord Jesus Christ, we are safe, and there is no other safety for time or eternity.
Here follows an excerpt from True Devotion on this subject:
There has been no other name given under Heaven, except the name of Jesus, by which we can be saved. God has laid no other foundation of our salvation, our perfection or our glory, than Jesus Christ. Every building which is not built on that firm rock is founded upon the moving sand, and sooner or later infallibly will fall. Every one of the faithful who is not united to Him, as a ranch to the stock of the vine, shall fall, shall wither, and shall be fit only to be cast into the fire. Outside of Him there exists nothing but error, falsehood, iniquity, futility, death and damnation. But if we are in Jesus Christ and Jesus Christ is in us, we have no condemnation to fear. Neither the Angels of Heaven nor the men of earth nor the devils of Hell nor any other creature can injure us; because they cannot separate us from the love of God, which is in Jesus Christ. By Jesus Christ, with Jesus Christ, in Jesus Christ, we can do all things. (True Devotion, §61)
So, you see that St. Louis has his eyes firmly fixed on Our Lord. He wants to attain union with Our Lord at all costs. But what is the best possible way to accomplish this? It is precisely through True Devotion to Mary.