Saint John of Kronstadt lived from 1829 to 1909 and was the archpriest of St. Andrew’s Cathedral in Kronstadt. Throughout his life he worked many miracles and was a tireless servant of God helping everyone who came across his path and advocating for the Russian Church to return to frequent communion. He was eventually, through the work of St John Maximovitch, canonized as a Saint in 1964 by the Russian Orthodox Church Outside Russia (ROCOR) and in 1990 by the Russian Orthodox Church. Below is a sermon he gave one Sunday to his parishioners.

If nowadays many Orthodox Christians live worse than Mohammedans and pagans, so that the leader of Mohammedans in Russia publicly and resoundingly proclaimed his praise to his co-religionists, that there are no such impious people among them as among Christians, who encroach on the life of kings...

... As for the preservation and integrity of our homeland and in it our Orthodox faith, rivers of blood were shed by our ancestors. Russian soldiers and leaders, who fought, pagans Mohammedans and Christians alien to the Orthodox Church, for the preservation of the Orthodox faith so that there were  rivers of apostolic, prophetic, and martyr's blood, and much suffering was endured by the Venerable Fathers and other champions of faith.

But what about us, children of the Orthodox Church? Do we preserve this most precious legacy, the Orthodox faith, do we follow its teachings, commandments, rules, statutes, advice...? Do we value our faith; do we consider it the greatest mercy of God, the greatest and the first benefit of life, that we have the happiness of belonging to the Orthodox Church, which is united, holy, conciliar, and apostolic? What shall we answer to these questions, if we want to answer according to our conscience?

To our shame we must confess that many, many of the Orthodox Christians not only do not have the Orthodox faith in their hearts and in their lives, but do not even have it in their tongues, and it has completely evaporated, or has turned into complete indifference to any faith whatsoever: Catholic, Lutheran, Jewish, Mohammedan, even pagan.

We hear from many that every faith can please God, that is, as if every faith is pleasing to God, and as if falsehood and truth, truth and untruth are indifferent to God. This is what ignorance of their faith, ignorance of the spirit and history of their Church, alienation from its life and worship have reached in many people; what a darkening of the concept of Orthodoxy, of non-Orthodoxy and non-religion...!

It is darkness, chaos, pernicious ignorance! The Christian, as a member of the Church, must know his faith and try to live by his faith, to be saved by his faith, because the enemies of our salvation do not slumber and seek our destruction at every hour, and not to abandon his faith as a specialty of some people only, or as an unnecessary toy peculiar only to a medieval age, or as the property of supposedly only uneducated mobs.

Those who dream in this way would do well to remember the venerable antiquity of our faith, modern to the beginning of the human race and its direct descent from God, and that in this faith people of every kind, rank, condition and sex have lived and been saved: both glorious kings and wise philosophers, and legislators and the greatest visionaries, noble and simple, rich and poor, male and female, the beauty and glory of humanity.

It must also be said, for the glory of the Orthodox faith, that no religion, except the Orthodox faith, can lead man to moral perfection or holiness and the perfect satisfaction of God, as is shown by the history of the Church and the imperishable, miraculous remains of holy men and women saints of the Orthodox Church, by which they completely pleased God, being still in their lifetime visionaries and miracle workers. So it should be by common sense that only perfect faith with all the divine powers, with all the spiritual armor of God against the passionate flesh, the world, and the devil can lead to perfection.

If nowadays many Orthodox Christians live worse than Mohammedans and pagans, so that the head of Mohammedans in Russia publicly, to the ears of all recently in St. Petersburg proclaimed praise to his fellow believers that among them there are no such impious, as among Christians, such a truly impious life of Christians should not, of course, in any way be a reproach to the Orthodox faith, which is unshaken in its foundations of truth and holiness, according to the promise of the Savior himself and according to the testimony of history. Such men, though they came forth from us, yet they were not ours in substance, but only in name.

Yes, my brethren, only the Orthodox faith purifies and sanctifies human nature, which has been defiled by sin...; it makes earthly things heavenly; it spiritualizes the fleshly; it makes the material things God-loving; it makes the selfish selfless and all-loving; it makes the unlikeable Godlike, and oh, the miracle! the divine! These are the miracles the Orthodox faith works in a person! Do you want to be sure of that? Read the stories of the lives of the saints and the history of the Church: you will see with your own eyes all of these miracles in the lives of the saints. You will see wolves turned into lambs, prodigals and harlots into righteous men and equals; money-loving men into merciful ones, voluptuous men into cautious men, men of power and earthly greatness and luxury into humble monk's garments.

Here truly were true Christians; here were angels in the flesh; on earth, heavenly citizens, and together faithful servants of the earthly fatherland, as were the 40 martyrs of Sebastia remembered today!

This is what our Orthodox faith can do to those people who sincerely contain it and follow its guidance!

From what does it not produce such a saving change in us? From our lack of faith or faithlessness, from levity, from a depraved and unrepentant heart; from the passions that have grown stronger in us and taken hold of us, from our distance from the Church, because many are not at all penetrated by the spirit and life of the Church, and many only hold onto it weakly and more formally and insincerely. This also gave birth to all the vices of our society today: murder, suicide, murder of the Tsar, arson, theft of public property, exorbitant luxury, debauchery, greed, and the pursuit of all kinds of sensual pleasures.

In order for us to be true Orthodox Christians, we must first of all have living, constant communion with the Orthodox Church, participation in its prayers, teachings, and sacraments, diligently study our faith and be penetrated by and live its spirit. We must be guided by its rules, commandments, statutes, and most importantly, restore in ourselves by true and deep repentance the image of a true Orthodox Christian in the image of ancient and new saints or better yet in the image of our Lord Jesus Christ Himself, who says I have given you an image to follow, that as I have done, so shall you do (Jn.13:15)

-St. John of Kronstadt, Sermons and Exhortations-