The word Amen is one of a small number of Hebrew words which have been imported unchanged into the liturgy of the Church. This word is attributed to our Lord in the Gospel of Saint Matthew some twenty-eight times, as well as in the Gospel of Saint John as a double formed, Amen, Amen, I say to you, some twenty-six times. As regards the etymology, Amen is a derivative from the Hebrew verb aman "to strengthen" or "Confirm".
In the Holy Scripture it appears almost invariably as an adverb, and its primary use is to indicate that the speaker adopts for his own what has already been said by another.
The familiarity of the usage of saying Amen at the end of all prayers, even before the Christian era, is evidenced by Tobit 9:12.
A second use of Amen, that which is most common in the New Testament, but not quite unknown in the Old, has no reference to the words of any other person, but is simply a form of affirmation or confirmation of the speaker's own thought, sometimes introducing it, sometimes following it, such as when Jesus says, Amen, Amen, I say to you…
Lastly the common practice of concluding any discourse or chapter of a subject with a doxology ending in Amen seems to have led to a third distinctive use of the word in which it appears as nothing more than a formula of conclusion.
As addressed by the question for us this week shows two special instances of the use of Amen that seem to call for separate treatment. The first is the Amen formerly spoken by the people at the close of the great Prayer of Consecration in the liturgy. The second is that which was uttered by each of the faithful when he received the Body and Blood of Christ.
Amen after the consecration
When we consider the "great Prayer of Consecration" a few words of explanation are necessary. There can be no doubt that for the Christians of the earlier ages of the Church the precise moment of the conversion of the bread and wine upon the altar into the Body and Blood of Christ was not so clearly apprehended, as it is now by us in this day and age when the Mass is celebrated in our own language. This is because back then and until the 1960’s Mass was being celebrated in Latin, a language not popularly understood in all places. They were satisfied to believe that the change was wrought in the course of a long "prayer of thanksgiving" (know to us as the Eucharistic prayer), a prayer made up of several elements — preface, recitation of the words of institution, memento for living and dead, invocation of the Holy Spirit, etc. — which prayer they nevertheless conceived of as one "action" or consecration, to which, after a doxology, they responded by a solemn Amen, an Amen that is to the fullest extent possible sung by the people as the great response to the gift of the presence of the Body and Blood of Jesus Christ now present on the altar.
Amen after communion
The Amen which in many liturgies is spoken by the faithful at the moment of receiving Holy Communion, that is the Amen spoken after the Minister of the Eucharist shows the hosts and says “The Body of Christ,” may also be traced back to early century usage. It was a common practice in the early Church that when anyone received Communion they responded Amen, and then kissed the hand of the bishop who had brought it to them.
The point for us to consider is that the practice of answering Amen traces back to the early centuries, in fact the first and second centuries, when nearly all of the Church fathers make a reference to supplying an illustration of this common practice. In this instance, we are affirming that we do believe it is truly the Body and Blood of Christ.
Finally, it is a little word, Amen, which indicates a strong affirmation, and translates in our present terminology as “let it be so,” or “I do believe.” This simple word expressed the faith we should have whenever we pray but certainly as we approach the Lord in the Blessed Sacrament.