He is one of the relatively modern saints (having lived one thousand years after the miracles performed by Jesus and the Apostles) who demonstrated throughout his short earthly life in service to God that actual miracles, not "fables" or "symbolic stories" take place when one is favored by God.
There is one miracle, performed by God and revealed by St. Anthony, that is of the most extreme importance for people to believe and to understand. Here is what happened:
Invited to preach at the funeral of a usurer, he took for his text the words of the Gospel: "Where thy treasure is, there also is thy heart."
In the course of the sermon he said: "That rich man is dead and buried in hell; but go to his treasures and there you will find his heart." The relatives and friends of the deceased, led by curiosity, followed this injunction, and found the heart, still warm, among the coins.
God had actually caused the heart of the sinful usurer to be removed from his dead body and found, still warm, by the curious relatives who looked in the usurer's treasure chest of coins. So this was not a "magic trick" or a "morality fable," but an instance where God performs a miracle in support of the preaching of one of his saints.
Consider also how St. Anthony is so blessed and good that he accepted the request to preach at a funeral (and conduct a Mass for the deceased's soul), even though St. Anthony was graced by the knowledge from God as to the dispensation, regretfully in hell, of the deceased usurer. True followers of God never "give up," they will pray for the worst of the worst, and continue to reach out to every soul who witnesses God's word at work.
So there are many things one must understand from this actual event, this miracle. One is that God affirms the genuine dire peril of those who for greed and avarice exploit others through usury.
If you have a scholarly mind, something should now "click" for you. Prohibition against usury is in the Old Testament, and also in the Qur'an.
Many modern secularists and Christians try to argue that Jesus "canceled out" the law of the Old Testament, which is most assuredly not true. Jesus warned that people should not think that his coming means that nothing from the Old Testament "applies any more" or that they can pick and choose in their liberality of "intepretation" which laws of God "still apply" and which do not. St. Paul and the other Apostles most certainly did not say that just because the Jewish law was not followed by Christians to demark themselves as the original Chosen People, that therefore all else that God allows and prohibits in the previous scripture should now be ignored.
This is one reason why God willed this extraordinary miracle, prophesied on the spot by St. Anthony, at the time and place that he did. Medieval and Renaissance eras were the time of extraordinary greed and avarice that were first breaking forth from the religious prohibitions that most had lived under prior to that time. In other words, it was that time and place that was the root of the economic and morality problems that we see today.
God willed and performed this miracle, so that St. Anthony could proclaim it, and people could see unquestionably themselves the meaning, exactly to warn against that trend that humans were beginning to follow, thinking that the prohibitions of the Old Testament should give way to everyday economic "practicalities" and developments that are rooted in greed, and not God's word.
Imagine how the relatives had a "come to Jesus" moment when they found, after looking with their own curiosity, in their own inherited treasure chest from the deceased usurer, and found his warm heart on top of the pile of coins.
Imagine all the "bank mergers" that have taken place in hell, through the centuries, and most especially in modern times. Hmm. Muslims have another thing to be very thankful for, since their faith has saved them from sinning in this regard, by adhering to moral principles in Islamic banking.
One of the subtle works of Satan was to encourage the Christian children of the Reformation to ignore the study of the saints, and thus isolate God's word, his will and his works to only the time of Jesus. The children of the Reformation have put all of the works of God through his saints "in a freezer," looking only, for the large part, at the parts of the Bible that they cherry pick (St. Paul, St. Paul, St. Paul and then for variety, more St. Paul).
I have never doubted their love of Jesus, and they will have their reward for that. But many of them love Jesus as they love the liberal friend or brother, ignoring that Jesus speaks for God the Father, the one and only God who continues to speak and to will specific actions throughout all time including to the present. Ignoring the specific lessons and events in the lives of the saints and how God manifested himself through miracles is one of the most dire mistakes of modern "enlightened" and "reformed" times.